A few things.
- Mega Mawile and Heracross are not the only viable TR Megas. Mega Amphy is more than viable in the playstyle, resists everything Talonflame can throw at it in addition to being really slow and having a monstrous base 165 attack and good bulk.
- A proposal regarding TR rankings. The OP states "Garchomp can be ranked in A tier as an offensive threat, Forretress can be ranked under A as supportive threat and Skarmory can be can also be ranked in B tier as a defensive threat." Couldn't this be extended to weather and TR? Excadrill is A+ as a Sand threat, Kabutops is B+ as a Rain threat, Porygon2 is C as a TR threat. Just a thought.
- Why is Crawdaunt terrible? It can bust through Azumarill with it's STAB, which is impressive considering Azu resists both STABs.
252+ Atk Choice Band Adaptability Crawdaunt Crabhammer vs. 252 HP / 0 Def Azumarill: 204-241 (50.4 - 59.6%) -- guaranteed 2HKO, 252+ Atk Choice Band Adaptability Crawdaunt Knock Off (97.5 BP) vs. 252 HP / 0 Def Azumarill: 198-233 (49 - 57.6%) -- 96.1% chance to 2HKO