I'm in the secondary stages of building what would be akin to a High UU/Low OU team in Pearl, and I seem to have hit a snag. One of the Pokemon on this team was supposed to be Steelix; however, I've found myself somewhat questioning if Bronzong would be a better choice. I'm hoping to look at the advantages and disadvantages of each Pokemon to see which offers the most team support.
Stats:
Steelix
HP: 75
Attack: 85
Defense: 200
Special Attack: 55
Special Defense: 65
Speed: 30
Total: 510
Bronzong
HP: 67
Attack: 89
Defense: 116
Special Attack: 79
Special Defense: 116
Speed: 33
Total: 500
When comparing stats, alone, Bronzong has a higher number of superior stats, but Steelix has a higher stat total, and nearly double the amount of defense, which is what I'm going for. However, Bronzong can take physical and special hits, which is a plus for it as well.
Abilities:
Steelix
Sturdy, Rock Head
Bronzong
Levitate, Heat Proof
Steelix's sturdy ability is very useful considering the environment I plan in has OHKO moves; however, Levitate from Bronzong is such a superior trait, that it's not even fair to compare them. Bronzong clearly has the superior trait.
Weaknesses:
Steelix
Water, Fire, Ground, Fighting
Bronzong
Fire (Levitate), Ground (Heat Proof)
In the terms of weaknesses, Bronzong has the advantage, always having just *one* weakness, as opposed to Steelix's four; two (three) of which are primarily special and working off its much weaker (65) special defense.
Resistances:
Steelix
1/2- Bug, Dark, Dragon, Flying, Ghost, Normal, Psychic, Steel (8 )8)
1/4- Rock (1)
0 - Electric, Poison (2)
Bronzong
1/2 - Dragon, Flying, Grass, Ice, Normal, Rock, Steel (7)
1/4 - Psychic (1)
0 - Ground (Levitate), Poison (2)
Here's where it gets tricky. Steelix has a good deal more resistances than Bronzong, and an electric immunity is awesome. But a Ground immunity is just as, if not more, awesome. However, Steelix has the very nice Dark and Bug resistances that my team needs.
Moves:
Rather than just list moves that both Pokemon can learn, here are some things that differenciate them from one another.
Steelix
Crunch, Thunderfang, Fire Fang, Ice Fang, Double-Edge, Roar, Stone Edge, Iron Tail, Taunt, Torment, Rock Blast, Rollout
Bronzong
Hypnosis, Confuse Ray, Heal Block, Calm Mind, Grass Knot, Light Screen, Psychic, Rain Dance, Reflect, Safeguard, Shadow Ball, Skill Swap, Solarbeam, Trick Room
Bronzong has more moves that it can take advantage of (mainly due to Calm Mind and an adequate special attack); however, with these Pokemon, I'm planning to focus mainly on support. Bronzong still has the advantage here due to the barrier moves (Light Screen, Reflect and Safeguard), but Steelix has Roar, which against the likes of Calm Minding Bronzong and Defense Commanding Vespiqueen, is a life(patience)saver. However, Bronzong can use Reflect to bring its defense up to Steelix's level. Steelix's roar makes it useful when partnered with Stealth Rock, however.
Tier:
Believe it or not, this matters. Not only am I looking for the Pokemon to best support my team in general, but one that fits the theme of low OU to high UU. If Bronzong is middle OU, then that bumps him out. I don't know how he's classified, though.
Items:
The environment I play in also has item clause. If the Pokemon can't survive without leftovers, that's a blow to it.
Movesets:
Finally, I'm looking for the Pokemon that would have good survivability, decent attack options, and overall good team support, both in taking hits and ensuring that the team is effective.
Steelix @ Leftovers
Trait: Sturdy
Nature: Impish/Relaxed
~Roar
~Stealth Rock
~Earthquake
~Iron Tail/Ice Fang/Stone Edge/Rock Slide
Bronzong @ Light Clay
Trait: Levitate
Nature:
~Stealth Rock
~Hypnosis
~Reflect/Light Screen
~Earthquake/Gyro Ball
These are the most supportive movesets for the Pokemon I could come up with. The purpose of these Pokemon is not to stand-alone but to support the rest of the Team. Both do this very well, and Hypnosis on Bronzong is very helpful. However, without Roar on Steelix, I'd have to use Whirlwind or Roar on another Pokemon, which could lead to trouble; especially because I already have a Ground-type damage dealer that functions just fine. Steelix also deals with Electivire and Weavile a lot better than Bronzong, and considering those two Pokemon cause my team issues, that's a major plus.
So, with all that I've stated, which of these two Pokemon should make the cut? My team is developed so that the differences between these two Pokemon can be made up.
Stats:

Steelix
HP: 75
Attack: 85
Defense: 200
Special Attack: 55
Special Defense: 65
Speed: 30
Total: 510

Bronzong
HP: 67
Attack: 89
Defense: 116
Special Attack: 79
Special Defense: 116
Speed: 33
Total: 500
When comparing stats, alone, Bronzong has a higher number of superior stats, but Steelix has a higher stat total, and nearly double the amount of defense, which is what I'm going for. However, Bronzong can take physical and special hits, which is a plus for it as well.
Abilities:

Steelix
Sturdy, Rock Head

Bronzong
Levitate, Heat Proof
Steelix's sturdy ability is very useful considering the environment I plan in has OHKO moves; however, Levitate from Bronzong is such a superior trait, that it's not even fair to compare them. Bronzong clearly has the superior trait.
Weaknesses:

Steelix
Water, Fire, Ground, Fighting

Bronzong
Fire (Levitate), Ground (Heat Proof)
In the terms of weaknesses, Bronzong has the advantage, always having just *one* weakness, as opposed to Steelix's four; two (three) of which are primarily special and working off its much weaker (65) special defense.
Resistances:

Steelix
1/2- Bug, Dark, Dragon, Flying, Ghost, Normal, Psychic, Steel (8 )8)
1/4- Rock (1)
0 - Electric, Poison (2)

Bronzong
1/2 - Dragon, Flying, Grass, Ice, Normal, Rock, Steel (7)
1/4 - Psychic (1)
0 - Ground (Levitate), Poison (2)
Here's where it gets tricky. Steelix has a good deal more resistances than Bronzong, and an electric immunity is awesome. But a Ground immunity is just as, if not more, awesome. However, Steelix has the very nice Dark and Bug resistances that my team needs.
Moves:
Rather than just list moves that both Pokemon can learn, here are some things that differenciate them from one another.

Steelix
Crunch, Thunderfang, Fire Fang, Ice Fang, Double-Edge, Roar, Stone Edge, Iron Tail, Taunt, Torment, Rock Blast, Rollout

Bronzong
Hypnosis, Confuse Ray, Heal Block, Calm Mind, Grass Knot, Light Screen, Psychic, Rain Dance, Reflect, Safeguard, Shadow Ball, Skill Swap, Solarbeam, Trick Room
Bronzong has more moves that it can take advantage of (mainly due to Calm Mind and an adequate special attack); however, with these Pokemon, I'm planning to focus mainly on support. Bronzong still has the advantage here due to the barrier moves (Light Screen, Reflect and Safeguard), but Steelix has Roar, which against the likes of Calm Minding Bronzong and Defense Commanding Vespiqueen, is a life(patience)saver. However, Bronzong can use Reflect to bring its defense up to Steelix's level. Steelix's roar makes it useful when partnered with Stealth Rock, however.
Tier:
Believe it or not, this matters. Not only am I looking for the Pokemon to best support my team in general, but one that fits the theme of low OU to high UU. If Bronzong is middle OU, then that bumps him out. I don't know how he's classified, though.
Items:
The environment I play in also has item clause. If the Pokemon can't survive without leftovers, that's a blow to it.
Movesets:
Finally, I'm looking for the Pokemon that would have good survivability, decent attack options, and overall good team support, both in taking hits and ensuring that the team is effective.

Steelix @ Leftovers
Trait: Sturdy
Nature: Impish/Relaxed
~Roar
~Stealth Rock
~Earthquake
~Iron Tail/Ice Fang/Stone Edge/Rock Slide

Bronzong @ Light Clay
Trait: Levitate
Nature:
~Stealth Rock
~Hypnosis
~Reflect/Light Screen
~Earthquake/Gyro Ball
These are the most supportive movesets for the Pokemon I could come up with. The purpose of these Pokemon is not to stand-alone but to support the rest of the Team. Both do this very well, and Hypnosis on Bronzong is very helpful. However, without Roar on Steelix, I'd have to use Whirlwind or Roar on another Pokemon, which could lead to trouble; especially because I already have a Ground-type damage dealer that functions just fine. Steelix also deals with Electivire and Weavile a lot better than Bronzong, and considering those two Pokemon cause my team issues, that's a major plus.
So, with all that I've stated, which of these two Pokemon should make the cut? My team is developed so that the differences between these two Pokemon can be made up.