Dent will take a five foot step just to make sure he can see the woman. And, yes, please don't attack Grimjaw just yet. I'm drafting a post in which Dent says that, give me a half a moment, please.
EDIT: OK, I'm done with battlefield control for the moment. I've had Dent freeze Grimjaw, and for Round 2, I had Dent cast bane, targeting Grimjaw, the reaver in S10, and the blue-skinned woman. I'm not planning any additional battlefield control type actions. From here on out, Dent will focus first on attacking and eliminating the reavers. He'll make sure Grimjaw stays in view. After the reavers are dead, we should still have enough time to square off against Grimjaw and (hopefully) take him down en masse.