Ha! 'Gainst 100-tons hitters like Hulk or Thor - sure it is FANtastic. But 'gainst normal humans an' not-so-high hitters like LUKE - sure he is. He's got his "goddamn mutant healing factor that makes [him] pretty damn undestructable" (c) Painkiller Jane. (;-) If it just for knockout - he can shake it off in SECONDS. The blow must be REAL hard to take Wolvie down for even minute - the blow that do SERIOUS internal damage. LUKE IS NOT SUCH HEAVY HITTER.
And.
Damn you, people! Stop wrightin' s#it 'bout "he needs some srenghth to cut through" an' so on! Don't be stupid! Wolvie EASILY cuts through TITANIUM alloys! I think it MUCH harder that Luke's skin!
(he-he, sure it is stupid that he can easily cuts through such things, but facts are facts, don't kick me, kick stupidous Marvel editors for this... (;-))