Lovie wouldn't be my first choice. And I definitely don't to want to have to start building a 4-3 defense. We finally have a solid 3-4 linebacker crew and a NT. shifting back to a 4-3 would be an AWFUL idea IMO.
I don't really want to switch to it for the same reasons either.
But we should be able to run a decent 43 w/ players on hand , maybe a hybrid type to switch things up would be okay.