Well, it depends on how you define "good" for a defensive team.  If it's by total points given up, then I suppose rebounding can be considered -- but then so can tempo, how poorly you offensively rebound; pretty much anything that can cause the other team to score more.  But if you go by things like opposing FG%, then techincally, no: rebounding does not affect defense. 
It's mostly semantics, but I also don't want new players to come away thinking a guy with higher REB is going to lower his opponents' FG%.

And I totally agree, you have to sacrifice something at DIII -- and the obvious advantage of ATH is that it effects every aspect of the game, so yes, it's better to have a 95/75 guy than 75/95 since the former will also be a better shot blocker.  I'm just a big fan of DEF, and didn't want new players to think they could totally ignore it :)