Correct me if I'm wrong, but those are just shield-weapons, right? And the anims are just that, I believe, and you can't swap between dual wielding and sword-and-board easily (because they use the same animation), correct? And your offhand weapon doesn't actually do damage or apply its effects, yes?
More or less, yes. It is a limitation of the game engine. As far as I can tell there isn't a way around getting the offhand to actually do damage without messing up damage ratios in general. You could try and simulate it saying "if attacking get weapon damage do this much x2" and time it to the animation play duration, but it seems sticky.
I'll have to check out UV, but I would be surprised if it was able to do this, getting offhand swings to inflict their own damage. Could be wrong though, just throwing another option out there.
EDIT: WOW! UV looks to be a truly epic mod. Must make use of a ton of OBSE functions I've not even delved into. Or Pluggy...
I can't believe I missed this before now. Also, it does look like it handles damage by both weapons.