Um...no? Bronzong is not closer to Dialga because Bronzong lacks offense and generally sucks on heavy offense teams due to being a huge momentum suck. Their functions are only superficially similar because they go on different kinds of teams. This is something you admitted yourself in your original response to Cranham. Klefki and Bronzong are both defensive Steel-types that find their home on balance teams, ergo they directly compete for the same teamslot. They are much more directly comparable. You would use one or the other on a balance team, but neither fits well on the heavy offense teams you'd generally want Dialga for. You're actually the one comparing apples to oranges here.
(As an aside, if you did want to compare Bronzong and Dialga...a key distinction is that Dialga actually checks Salamence, does better against Rayquaza than Bronzong, and is more reliable at keeping up hazards due to actually having offense.)
How are Spikes and checking Dark-types arbitrary? They are distinct advantages Klefki has over Bronzong. It is harder to come by solid Darkrai checks than Ground checks in this metagame. You're not actually countering the point I proposed, you're just flipping the question without addressing it
1. Every team needs a Stealth Rocker. Every team needs Primal Groudon. It is a popular option to designate it as the Stealth Rocker. But Primal Groudon is much more versatile than being every team's Stealth Rock slave; it gets Swords Dance, Substitute, Thunder Wave, Rock Polish, Rest + Sleep Talk, and so on. So, if one wishes to take advantage of said moves, what would the next step be? Finding a Stealth Rocker for the team. Look at the Pokémon listed from S rank to, say, B-. I see four options: Deoxys-Speed and Excadrill for hyper offense, Dialga and Tyranitar for bulky offense, and Mega Diancie and Bronzong for balance. Ignoring hyper offense, Stealth Rock Tyranitar is niche in that it should only be used with its partner in Sand Rush Excadrill, and Mega Diancie takes up a Mega slot, therefore these two Stealth Rock users are quite restrictive to the rest of the team-building process. This leaves us with Dialga for bulky offense and Bronzong for balance. Choosing either limits you to the bounds of their respective play-styles, but ultimately, the choice of one over the other opens up a different set of doors. Dialga allows you to play much more offensively with the likes of Geomancy Xerneas and Mega Salamence at the cost of being unable to use Pokémon that kill momentum, whilst Bronzong allows you to play much more balanced to synergize with Pokémon like Mega Gengar and Arceus-Dragon.
2. Their similarities aren't superficial; the fact that these two Pokémon are equally viable candidates in the team-building process as a team's Stealth Rocker, yet are separated by about two ranks-worth space, is bizarre. Moreover, what I "admitted" to has to do with "Bronzong [lacking] offense and generally [sucking] on heavy offense teams due to being a huge momentum suck" in that, while this is indeed true, I am agreeing with you, heavy offense is not the only archetype available to build with, so the fact that Bronzong sucks on offense speaks not of its viability only unless you wish to pretend that slower and bulkier balance builds just don't exist.
3. Saying that "Klefki and Bronzong...directly compete for the same teamslot" is the aspect of your counterargument I take most issue with. This is flat-out false, yet you seem to take no issue with using it as a blanket condition to invalidate my argument. So, let's be clear: you choose to add the former to your team as a check to Darkrai, Yveltal, Xerneas, Mega Salamence and so on. On the other hand, you choose to add the latter to your team as, first and foremost, a Stealth Rocker able to both set them up and keep them up with reliance, as well as a check to Xerneas, Arceus-Ground, and so on.
Finally, let's describe Dialga in the same fashion: you choose to add this to your team as a Stealth Rocker able to set them up with reliance, as well as a check to Mega Salamence.
Further, this is all without mentioning that Klefki has no room for Spikes if it truly wishes to check Xerneas as both Thunder Wave and Heal Block are required, and Dialga fails to keep Stealth Rocks up as reliably as Bronzong due to the existences of Defog Arceus-Ground and Rapid Spin Sand Rush Excadrill.
I believe our point of contention lies in the fact that I equate Bronzong to Dialga because these two are the best non-Primal Groudon Stealth Rock setters on balance and bulky offense, respectively, whereas you equate Bronzong to Klefki upon the sole basis that the two share similar typings.
Subsequently, the bulk of your post dismisses my argument on the above basis, and the rest consist mostly of nitpicks. To address a few things: if Bronzong uses either Skill Swap or Trickroom on the Mega Gengar switch, it evades being Shadow Tag bait, and what you said about Bronzong can be said of Dialga, too, at -2, something not uncommon due to its two other moves being specialised coverage for Magic Bouncers and Defoggers. Also, never had I suggested for Bronzong to be any team's designated check to Extreme Killer Arceus or Kangaskhan; I was simply bringing attention to the fact that all of these offensive threats have numerous viable sets, and that Bronzong has an easy time walling the favorable variants as long as you can identify it correctly.
P.S. It's literally the first round of the Open, those usage statistics and win rates are unscientific, you should know that. On the contrary, according to the 1760-and-above Ubers ladder's usage statistics as of July (
http://www.smogon.com/stats/2016-07/moveset/ubers-1760.txt), 26% of Mega Kangaskhan ran Crunch and 59% of Extreme Killer Arceus ran Shadow Claw.
