For sure,Tarik is inconsistent.I believe he performs his best once he is allowed to do whatever he want.His recent form upgrade confirms the same as Stan and tarik are pretty close and you might have noticed the play he makes especially on Inferno moving differently across map in every round.I think this is what he missed in mibr.Same goes for stewie somewhat.
I don't think Fallen would work. It seems that his strats have been outdated for a while now. If he worked on making some new strats that fit Liquid's style and was able to communicate well enough in English then maybe. But with what he's been doing strategically on MIBR won't cut it.