Would I be happier of Delonte was 6-8 with an incredible wingspan? Sure.
However, he's not. But we shouldn't mistake our lack of a true small forward as a reason for not liking this move. Aside from the fact there's zero risk, despite being somewhat repetitive with Bradley and Wafer, West is likely going to be better than either. And that's certainly a plus.
Let's not forget two years ago he was starting and playing 33 mpg on the Cavs and wasn't too bad last year either. He has the talent to start (at least on some teams) in this league. Having him on our bench is great.
Well, even if we used Delonte as a defensive back-up for Pierce he wouldn't be giving up any height compared to what we had last season, in Tony Allen. However, while both Delonte and Allen are 6'4" (same height as Wade, yet still a tad short to be playing small forward) Delonte still concedes 33 pounds to Allen...
Maybe if West used the 10 game suspension as an impetus to try and bulk up a little, but now I'm just wishful thinking...lol, if worse comes to worse we might have to have, say Glen Davis guard the 3 vs some teams - that or help defense + double teams whenever there is a mismatch 
I've always liked Delonte better as a player than TA. Props, though, for noting they're the same height/length. I think Delonte has the IQ, quickness, and hustle to be a top defender as well, but adds some ball handling, shooting, and playmaking. I'm not sure what other players on this team right now would actually, on instinct and without hesitation, dive for a loose ball besides Delonte. Perhaps Rondo, Nate, BBD (falling on it, rather than diving, perhaps), and...um...the rookies won't see the court to have the opportunity, most likely...so I guess...that's it?
He brings something we need. I like it.