Personally I think Clarke's been going backwards for a while at CCFC. I don't think it's worth blaming either the player or the manager for it, perhaps it's just the combination of the two that's not working.
I hope, like Christie at Derby, he returns to some decent form at Yeovil and it all works out for him. Why wouldn't anyone want a Cov kid to do well, regardless of where he plays.
As for Martin, I don't really remember him being either outstandingly good or bad. That's not always a bad thing in a centre-back, imho. There's something to be said for unfussy, understated performances in the heart of the defence - as long as the opposition aren't scoring I'm happy.