Nightwing isn't even close to being faster. Unless you seriously think he can keep up with Spider-Man when he can't even touch Batman when Bruce doesn't want him to. He's maybe more acrobatic than Logan, but that is it. His intelligence isn't going to be a factor and I'm not sure where you jump to the conclusion Nightwing wins when
A) He is weaker. (which you admitted)
B) He is slower. (since it's false to assume he is faster)
C) His durability is far less. (Admitted)
D) Less skilled by a significant margin.
And with Dick's penchant for using melee combat above gadgets puts him at an even higher disadvantage. Just throwing that out there before people start spamming the "Nightwing has sonics argument" when they fail to realize his preferences in battle show that doesn't fly. From the start he is at a disadvantage. Logan's tagging him within the first few blows thrown and Nightwing's escrima sticks aren't doing much and a slash from Logan already sets the pace for him to fall soon after.
Wolverines win. Their damage soak and output surpasses that of the Slades and that is what mainly wins this for them. The environment will make the Logans feel at home, but I feel like Slade's adaptability would eventually lessen that.
While I disagree with how the fight went down in AvsuX Versus 2 being that Cap took down Remy as easily as he did, I do agree with the results of the fight with Cap winning and how the shield would treat being charged.