Hi, Nice team however you seem to have to have a weakness to Char-X and Char-Y.
Looking at the team you said that your Clefable helps you against Charizard-X however even a unboosted DD Jolly Char-X can easily 2hko your Clefable as shown by this calc:
252 Atk Tough Claws Mega Charizard X Flare...