[Varyon]

Out of town, so can’t check my pdf, but some considerations.

First off, if weight is a factor, don’t forget the character must shift the weight of both characters. Regardless of how much Cassandra has penalized the zombie’s ST, Maxi still has to deal with their weight.

As for Cassandra spending CP to penalize the zombie’s defense, I have no problem with this. IIRC, spending CP out of turn to penalize an attack on you is already a thing, this is just an extension of that. Indeed, I’d have little problem with a character spending reactionary CP to penalize a foe’s defense against a strike, even one from someone completely uninvolved in the grapple. That said, unless the two characters working together have Teamwork or similar, the efficiency is probably reduced (requiring one to spend more CP for the same effect, relative to if they were the one in control).