Hill finished his college career with .390 3pt% (on 5 attempts per 40) and .766 FT%. His career NBA FT% is .831. It was a matter of time and gaining confidence, before he started knocking down decent amount of shots. Just for comparison Danny Green shot more 3s this season at .332% than Solomon Hill in his career. Now anyone thinking Hill will continue to make 50% from 3 is in for a big surprise, but 36-38% outside shooting can be expected. As for post game Hill was ok there in college, but Pacers played two inside bigs most of his career.
We'll see if Hill is able to hit 3's above league average. If he does, he is certainly not a borderline starter anymore. His defense was always good. The only knock on him was his "lack" of floor spacing.
Like I said - I'm certainly not advocating, that Barnes (nor Hill) is a star player, but borderline starter sounds a bit odd for me, when most teams are searching for 6'6 to 6'9 guys able to defend the 3 and hit the 3 on offense.
In my mind Barnes would certainly start for the Lakers, the Heat (unless you think Deng is better in the long run, which I doubt), the Bulls, the Raptors, the Rockets, the Celtics (if they decide to play Crowder at PF full time which is questionable), the Hornets, the Clippers, the Knicks, the Blazers (I think he is a bit of an upgrade over Aminu or Harkless), the Grizzlies, the Kings, the Pelicans, the Wolves (if Wiggins can play full time SG), the Wizards, the 76ers, the Suns and the Nuggets as long as Chandler isn't healthy.
That are quite a lot of teams. And even if some teams don't have the cap space to sign him (I personally don't look for other teams cap space), he will have a lot of suitors in FA. He is still only 23 (almost 24) years old, has tons of playoff experience under his belt, will hit his prime soon and fits the long term plans for most teams. A guy like Carroll is 29 and signed a 4 year 60 million deal and the cap is going up again.
20 million is a bit of an overpay, but given the amount of teams, that should be interested, it sounds realistic.