My current team is Chesnaught, Aerodactyl (mega), Goodra, Conkeldurr, Aegislash, and Clawitzer. I was thinking of replacing Aerodactyl with Mawile, but that would leave me with 3 weaknesses to fire...Thoughts? Should I replace both Aerodactyl and Chespin?
I like Chesnaught, but he's not my favorite. If you build him right, he can play pretty well, but I'm not really a tanker. For me, I'd swap out Chesnaught and leave Aerodactyl. I don't know that I'd put in Mawile, but Chesnaught's standard strategy doesn't work for me.
As for you, if you can tank, go for it. I haven't done a whole lot of research, but I think Mega 'Dactyl would better serve your team than Mega Mawile.