Your team does have a electric/grass weakness. I recommend that you change rotoms set to be near max speed, full spatck and rest in hp. Maybe something like, 248 timid, max special attack and then 8 in hp, with leftovers to take on grass and electric types. I feel that overheat shortens Rotom's usefulness, so I also recommend that you use Hydreigon over it.
You can run fire blast or flash cannon if you feel that you need it, for things like Forrestress. Hell, you could even throw specs on it too. Those would work well. Hydreigon is is strong check to electric and grass types. You could even go specially defensive Hydreigon, with dragon tail and crunch instead. You also might have a hard time dealing with faires and hydreigon won't help.
A cobalion might help, as it gives you stealth rock support and a nice fast, fairy check. I feel that he would fit well instead of Crawdaunt.
One last thing, Aerodactyl does really, really well when it is used as an offensive threat. It can use pursuit and aqua tail, which provide nice coverage. You'll most likely get more usage out of this set.
I hope all of this helps friend!!