Remove baton pass/speed boost on SAya, and remove rock bullet from sendai and MAYBE it'll be possible. who am I kidding they are both OP even with those changes
Or you could just go full on Smogon and implement
SPEED Clause (i.e. ban Speed Boost if it's on a Baton Pass user)[inspoiler], or just don't run Speed Aya with Speed Boost...[/inspoiler]
As for Sendai, shave 10~20 points from Attack, Defense, and Sp. Def, and add it towards Sp. Atk (or Speed).
NoIdon'tseeanyotherbalancingissuesguyswhatareyoutalkingabout?