Alrighty, sorry this took so long, I had to study and stuff.
First of all, Air Balloon > Leftovers on Heatran Air Balloon on Heatran allows you Check Pinsir, and get an earth power off on Mega Charizard X before killing it with Quick attack from Pinsir. Without it, Charizard X and Pinsir would Wreck your team. (Pinsir is semi-checked by Terrakion but you have to watch out for +2 quick attacks) also, Stone Edge > Ancient Power on Heatran. Since Mega Charizard Y has higher Special defence, stone edge hits harder than ancient power on heatran. Also, it still OHKOs talonflame, like ancient power.
Next, Thunderbolt / HP Fire / HP Fighting / Roost > Surf on Latios. Surf only really hits ground types without lowering you attack, as STAB Draco Outdamages SE Surf. Thunderbolt can help latios take care of Azumarill, hp fire nails Ferrothorn and does solid damage to bisharp, HP fighting nails Bisharp and Tyranitar, both can pursuit trap it otherwise. Roost gives you recovery, which is always a plus on offencive pokemon.
Most of the other stuff that was wrong has already been changed.
Hope This Helped!
Good day to you sir~