Basically it comes down to -- Miller should no doubt be better than Varly. That's a given. But Benn is ASTRONOMICALLY better than Nyquist. So with your cats, ask yourself, do you not give an eff about retaining Benn? If you don't need him then do it. I don't know roto and I find it baffling that this could possibly work in your favour. But to your question
Miller >> Varly
Benn >>>>> Nyquist