1. Even if we got Kenneth Faried Mike D will not play him. Can't shoot 3's, and Mike D would rather run Amar'e out there for 42 minutes a game than play Kenneth Faried. At least when it comes to Shumpert he doesn't really have any other choice.
2. Brewer didn't get playing time in Dallas because he joined Dallas with like 3 months left in the season. Also a player like Corey Brewer is more of a regular-season guy than a guy you really use a lot in the playoffs. In the playoffs because you have more days off you can use a shorter rotation, whereas in the regular season you need more depth because you don't have as much time off and you need to rest your stars for the postseason.