But there would need to be a battle field experience stat for each weapon skill, as you may find unorthodox ways to use a weapon while battling unusual enemies or while fighting in circumstances that you don't get while training. You could be the king in the fencing class, but if you don't know how to improvise in the real world, you won't beat that legendary warrior who has defended the land from thirteen massive attacks with little back up.
For the first one, that would make more sense as battlefield experience for each creature. There aren't that many creatures that are odd (it can't be that different to fight goblins than to fight dwarves) and honestly most of that stuff could be "passed down" from champions (Imagine champions holding "what to do on the battlefield" classes). And actually, if that "legendary warrior" was also using fencing, and wasn't as good as you, you could whip his ass. One on one duels to the death are... well, that's sparring, just to the death. Bad example.
To the above: Two stats makes more sense. Weapon skill is technical proficiency with weapons, and battlefield exp. is experience under battlefield conditions (more resistance to fear, avoiding traps, spotting ambushes, more ability to fight while wounded, and some increase in skill, but not much).
To give you my concept of it, Battlefield experienced people are almost never going to be able to beat somebody with less battlefield experience but more weapon skill in a straight up, controlled fight. However, battlefield exp. guys are the dwarves who won't flee (military dwarves DO need to flee, it gets annoying when your concious dwarf with a broken weapon arm attempts to punch a squad of goblin axe users to death when he should be fleeing) and would be more effective on the battlefield, especially if they were squad leaders and sent to attack other bases (of course, this is all when the army arc comes out). Putting it all into weapon skill not only leaves the problem of forcing all your dwarves to be stuck in mediocricity in what is easily trainable, but also means that all the GOOD things about battlefield experience cannot be expressed. Also, Beowulf wouldn't have been as badass if he didn't kill monsters, but he would still be just as effective with a weapon.