So basically, you're saying make sure your starters can defend the perimeter decently? Is it a big deal if your bench players aren't as strong in that area, except for maybe power forward?
Well, at some point you might have to make compromises - very few people are equipped to have crazy OD all over the floor, and sometimes even then that bit about the big men guarding (and constantly fouling) the guard might kick in. My textbook example is this game, where my starting lineup had crazy OD (I think this lineup was something like 16 - 14 - 17 - 14- 10 OD, with defensive switches, and 16, 11, 14 and 14 on the guys I planned on playing from the bench).
(65823062) Unfortunately, his foul drawing PG and my extremely fouly C played slapass all game, or at least until the C fouled out and then someone else got to continue fouling.
But, yeah I've run enough outside offense at high enough levels to actually be excited to face zones in most cases. If you have a SF that doesn't have great OD, you can be sure that he'll be the guy reported to be defending the most threes, because the guy he's guarding on a particular play is closer to "open".