As a couple of others have said, I wouldn't worry too much about our back-court right now.
I actually think those three guys compliment each other pretty nicely, and I think that's a big reason why we had so much success to close out the season.
Bradley + Smart gives us an elite defensive back-court, in which Bradley can handle a good deal of the scoring and Smart can be the ball handler / facilitator. Smart has a done a better job of the latter then people give him credit for, though he still has a long way to go.
Smart + Thomas gives us a deadly two-way team where Smart can take on the defensive responsibility of guarding the opponents best offensive guard so that Thomas can focus purely on scoring and playmaking.
The only combination that is questionable is the Thomas + Bradley one, but even that lineup isn't terrible. Thomas is an excellent ball handler and a pretty good passer, and when he's on the court Bradley has a big offensive load taken off him, so he can focus more of his attention on defensive pressure. It's also a pretty dangerous lineup offensively because Bradley is a pretty decent outside (and midrange) shooter, so if defense cheats on AB to double/trap Thomas, Bradley is very capable of making them pay with his jumper. There are certain teams that have enough size to put this combo at a big disadvantage, but there are also a lot of small back-courts in the NBA that a lineup like this can compete fine with.
With any combination of Thomas, Bradley and Smart we have a quick back-court that can punish teams on the fast break. I especially like the Smart+Bradley lineup for that, because they can generate a lot of turnovers with their defense and then run, run, run.
In terms of transition game, a lineup like Thomas / Bradley / Turner / Olynyk / Zeller could cause quite a bit of trouble on the fast break, and I think I've even seen BS go with a three guard lineup (Thomas / Bradley / Smart) on occasion which has fared surprisingly well.
Do you do a sign a trade with Bradley ($7.2M) for which of the following FA's
A) Wesley Matthews (current earnings (7.2)
B) Danny Green ($4.0)
C) Gerald Green ($3.5)
D) Rodney Stuckey ($1.2)
Wesley Matthews - probably not. A sideways step I think.
The others, definitely not.