Any formation that leaves lukaku on his own is diaster waiting to happen. Liverpool will isolate him and then he will start drifting back to the middle of the park to get the ball.
We need two up front.
I think if Mirallas/Pienaar were playing better they would regularly move more and be able to get close to Lukaku and link with him when the opportunity arises.
Barkley if played also seems to have enough of an understanding with Lukaku, it's just his decision making letting him down.
I don't think the change of formation is worth it, and I doubt Martinez will go for two up top.