The team is at its best in terms of pokemon since you can't use heatran.
You could try a choice banded Arcanine, E-belt is good if you can hit super effective on almost everything the metagame has to offer. Your set has no crunch so psychic/ghost wont give you the E-belt effect and dragons wont trigger it even if you have crunch. Where as with choice band you can almost always go for a flare blitz (STAB+sun+band = alot of dammage)
Some calcs:
252 Atk Choice Band Arcanine Flare Blitz vs. 252 HP / 252+ Def Reuniclus in sun: 339-400 (79.95 - 94.33%) -- guaranteed 2HKO
252 Atk Arcanine Flare Blitz vs. 252 HP / 252+ Def Reuniclus in sun: 226-267 (53.3 - 62.97%) -- guaranteed 2HKO
252 Atk Arcanine Flare Blitz vs. 252 HP / 252 Def Latias in sun: 111-131 (30.49 - 35.98%) -- guaranteed 4HKO
252 Atk Choice Band Arcanine Flare Blitz vs. 252 HP / 252 Def Latias in sun: 165-195 (45.32 - 53.57%) -- 2.34% chance to 2HKO
252 Atk Choice Band Arcanine Flare Blitz vs. 0 HP / 0 Def Latios in sun: 235-277 (78.07 - 92.02%) -- guaranteed 2HKO
252 Atk Arcanine Flare Blitz vs. 0 HP / 0 Def Latios in sun: 158-186 (52.49 - 61.79%) -- guaranteed 2HKO
As you can see some pretty big improvements. Not to mention you can clean up late game with banded extreme speed.
Another thing you can change is scizors EVs , only slightly.
he only needs 164 speed EVs to outspeed adamant toxicroak, anything more then that feels like a waste of bulk. The remaining EVs can be put in HP, so basically:
88 Hp , 252 Atk, 164 Spd.
You can verify this here :
http://www.smogon.com/bw/articles/ouspeed_tiers