In my first league game I ran motion and my SF/PF were a combined 7-9 from 3 PT range (attempting 5/4 apiece). Of course, matchups and OD of opponents is a factor. But yes, those outside offenses will get your bigs involved IF they can shoot a little.
I've also noticed that as my PG & SG passing improves, the other players tend to shoot more. Seems that way, at least.