Nice team. I read that Bronzong is primarily for Mamoswine and Dragons that would otherwise cause problems for the team, but considering that Bronzong has no recovery move and therefore is one of those Pokemon in the long run is knocked to the sound of attacks against the dragons and Mamoswine seconds me is much better to use Skarmory
who owns Roost to recover HP, it can also place the Spikes, and wipe out the most dangerous enemies using Whirlwind.
By placing Spikes Skarmory so I would say that you can remove Ferrothorn for Amoonguss
that recovers HP more easily thanks to Regenerator, Amoonguss also gives you the important opportunity to sleep an opposing pokemon like Ferrothorn and Rotom-W can come up with any move has the advantage that even if it takes a Will-o-Wisp can attack however with Giga Drain without the degradation of power, also has a switch for more Keldeo and the moves Water in general, Amoonguss is also an excellent switch for Keldeo Subcmind that would give problems, Amoonguss with 28 Evs in special attack is able to break his Substitute with Giga Drain, and is a Pokemon with which most suffer the Fight moves.
Amoonguss is also a good Pokemon against Breloom in every set, thanks to HP Ice can kill him with some attacks, and with the evs in HP and defense and typing resist his moves and Grass Fight.
Other important things I notice is that your Hippowdon is not at all able to also undergo special moves, so there are no differences between defense and special defense, I always use this evs spread thelatest whom I am well: 252 HP / 124 def / 132 SDef Impish
This way you get at least a solid defense and a decent special defense, able to collect quite well special moves as well as individuals, with the first evs spread of any special move was a nightmare for that Hippowdon.
To suggest this Latias evs spread: 252 HP / 4 SAtk / 252 Spd
with more evs in HP becomes stronger.
Blissey recommend it Calm> Bold
, the better to resist Rock Polish Landorus special with a little 'of residual damage on the switch with two Focus Blast you would send most if not KO KO, while with his Focus Blast Calm especially take them better.
Good luck, with your team!