Venom Snake having a different voice actor ended up being OK for me. I think Sutherland handles Venom's smaller and depressed dialogue betters. That said, it's hard for me to imagine Sutherland doing Naked Snake. Sutherland commands much better but Hayter does levity and vulnerability, even wit, much better. The comedic levity with Paramedic, the wit and banter with Ocelot, and ignorance with EVA and Sokolov, and vulnerability with The Boss were superbly performed and casted.
Peace Walker is an interesting middle point because while I can't imagine Sutherland doing Snake Eater, when I recently replayed Peace Walker after beating Phantom Pain and then consecutively Snake Eater again, I found at times in Peace Walker I may have preferred Sutherland. Somewhere during Metal Gear Portable Ops and Peace Walker, Big Boss loses the levity and vulnerability that Hayter captures well and essentially becomes Sutherland's Big Boss and Venom Snake.
The reason it works for me is because Venom Snake in general has become such a different character that any disparity normally associated with a voice acting switch isn't there. But had it occurred during Peace Walker, even, it may have worked. Portable Ops, interestingly, is actually the most defining moment for me... the scene with the first recruited Soviet soldier, the last scene with Cunningham, and especially all the dialogue with Gene, transitioned Naked Snake into Big Boss even more than Peace Walker.
So, it's rather interesting because I end up appreciating both their roles: as Snake becomes Big Boss, Sutherland commands his new tone well, gives him a tone of control and certainty,leadership; but the defining part of Naked Snake is his lack of command and control -- his nakedness. And Hayter captures his iconic Snake ignorance, levitity, and vulnerability.