A couple points form me:

Adam, the level of punching/striking is far greater in boxing, but you need at least one more dimension to have any chance in mma. Granted, boxing, IMO, is the best foundation to have for any combat sport. As an aspiring fighter, I'd start there, then get into judo and/or bjj while evolving my stand up to muay thai legs and elbows.

Also, in his prime (I don't care what anyone says) there has never been a harder, more deadly puncher than Tyson. Liddel would have no choice other than try to take him down, otherwise Mike would DESTROY him. And I mean DESTROY. Chuck hits hard, yes, but he's NOWHERE NEAR as hard or proficient as Mike once was.