Scarfed Gengar is not bulky enough/has the right typing to utilize the trick set imo. He is very suspectable to Knock Off. You say you tend to cripple Gliscors and Ferrothorns using Trick often - but who switches in (or even fights) a gengar with gliscor/ferro? Most Gliscors do not use Knock Off and it can't poison you... and Ferro is 2hko'd by Focus Blast. I'd rather 2hko a ferro via focus blast on the switch (given that it may not even happen) than give it a choice scarf. Save the scarf for something that you can't handle, you know? Just nitpicking I guess. Substitute allows you to bypass status and leech seed anyway, and gives you a more flexible path of opportunity if you sub on the switch it. With a Life Orb, Gengar can act more of a wallbreaker, damaging threats much harder than without it. Also, use Sludge Wave, not Sludge Bomb, easy 5 more base power which could make a difference. I know you said you're not changing Scarfgar but I just wanted to say . On the bright side no one will really suspect a scarfgar and not think twice about switching in a Trick suspectable target. I've never used it, so I digress.
Definitely change your Gliscor's EVs with the assistance of the above posts, Gliscor does not need 252 defense or even 252 hp in this meta. Also with the lack of Will-O-Wisp and Flare Blitz on Talonflame, I am unsure how you get around Scizor. I honestly dislike the use of Drain Punch on Mega-Lopunny as her defenses aren't exactly top-par, and she is designed to dish out a load of damage/fake out pivots without taking much damage anyway. I prefer High Jump Kick, the risk taken is well rewarded. If you dislike the risk of High Jump Kick than you can use Power-Up Punch, which racks up damage nicely and can make your opponent second guess switching into Lopunny. Definitely don't get rid of Ice Punch though, you need it to get past dragons. Defog Latias without Roost is risky as she can easily get worn down via status/damage (omnipresent Keldeo will burn you on the switch), then you lose control of hazards for the rest of the game if she is not kept alive, hindering Talonflame's potential. You also use Healing Wish AND Defog, which is not the wisest choice as once you Healing Wish than you can't exactly kiss Stealth Rocks (and Keldeo) goodbye. I am questioning Talonflame's set in general - bulk up is not exactly the greatest offensive boost, and you only have one offensive attack (which can be easily resisted). And with no attack investment you may find yourself dealing very little damage in tight situations where you can't afford to bulk up (say if Latias gets trapped and you get stealth rocked). Changing Bulk up to Will-O-Wisp will make you one of the best wallbreakers - which is necessary as your team is really pure offensive. You can even still use Bulk-Up with Will-O-Wisp instead of Taunt, which may help you cripple some threats anyway. On the Taunt you're going to want 16 or 24 speed EVs on Talonflame so you can outspeed other specially defensive Talonflames and Taunt them, giving you the upper hand and potentially momentum (considering how popular specially defensive tflames are now adays with Mega-Charizard Y).
