Okay so, this looks like a pretty solid team. But after looking closely at your EVs I kinda almost wanted to throw up. Here's a crash course on EVs for you. When something has a huge base HP, it's better to invest more in Def or SDef. Also try to have an odd HP number on things weak to rocks so you only take 49% from rocks when you're 4x weak to them and only 24% when you're 2x weak to them. (This is mainly about Zard X.) Also try to do a little research and numbers work to see what you can outspeed with +1 and +2 boosts and adjust your speed EVs accordingly. Also please if you're running Assault Vest on something, put more than 4 EVs into your special bulk.
Now onto fixing these EVs.
With how massive Chansey's base HP is, I recommend going 4 HP / 252 Def / 252 SpD. You just get a hell of a lot tankier that way and your Wish passes still heal a shit-ton.
Go for a more split-defense set on Ferro. Something like 252 HP / 96 Def / 160 SpD so you can tank hits from both sides relatively well.
Like I said before, please put more bulk into your Assault Vest users. Go with a clean 120 HP / 136 Atk / 252 SpD to increase your bulk and to keep you around longer to do more spinning for Zard and that nifty VoltTurn core you've got.
Also, Rotom-W is WAY better as a Defensive set now. It has the perfect mix of Defensiveness and Offensiveness with these 252 HP / 212 Def / 44 Spe EVs and a Bold nature instead of running specs. Also slap some lefties on there and put on Pain Split instead of Trick. (For hopefully obvious reasons.)
So now onto the main attraction, Zard X. Charizard is 4x weak to rocks pre-mega. So it is only natural to want to run some kind of recovery on it. (A-la Roost) And the Speed EVs really are unnecessary on something that is most likely going to get a +2 boost. I recommend these 144 HP / 252 Atk / 112 Spe EVs as you outspeed the most relevant scarfed 'mons after +2. Also scrap Flare Blitz for Roost because Dragon + Ground is already perfect coverage. And Use Dragon Claw over Outrage as usually you want to play rather safely with your Zard X and D-Claw still hits really really hard.
Good luck with your team! :]