Deathstrike can cut them all to ribbons and is all around the toughest one. Marrow and Beast just aren't durable enough to fight the regenerators, even beasts's healing factor is mediocre in comparison.
If the wildchild pulls an exceptional fight out of his ass - which is rare as his showings are all over the place - he could overload deathstrike's cybernetic self-repair system. I think LDS would take a majority.