If hitting and wounding were opposites, like you rolled high for one and low for another, I could see this working.
Though again that would prevent units (such as Orks) from ever wounding hard-to-wound models, as they wound hit on a 5+ but need a 3 or less to wound - so none of the hits would ever wound!
I guess you could add the to hit and to wound together and roll a D12
for it - EG orks needing 5's to hit and 4's to wound need a 9+ on a D12
to hit and wound. 12's always succeed, 1's aways fail.
It's actually a smooth way to go, actually, not sure how it affects the probability though...
5's then 4's is 1/3 followed by 1/2, so 1/6 chance of success
9+ on a D12
is 1/3 chance of success
so no, not comparable!
2's then 2's is 5/6 and 5/6, so about 0.7 if I'm maths-ing correctly.
4+ on a D12
is 3/4, so 0.75
so that side isn't so far off...
perhaps if you had to exceed it...
10+ on D12
is 1/4, closer to 1/6 (3/12 as opposed to 2/12)
5+ on a D12
is 1/3, or 0.66... so stil lnot quite the same.