Williams has probably had the best 6 game stretch of his NBA career since he got here. He shooting at an unsustainable 53% and has doubled his career steals average per game. The question is can he maintain this going forward? He is young enough that it is possible but it will be difficult coming off the bench. Gay is a border line all-star talent who absolutely will start and I think Williams will have to come off the bench. Unfortunately I don't think either has the skillset to really excel at PF night in and night out. Especially since we need our PF to take the harder defensive assignment out of the opponents PF and C to try and keep Cuz out of foul trouble. I think we will have to trade either Gay or Williams. And I bet Williams has more trade value than he did 6 games ago.
The biggest issue as I see it is what Arkitect indicates above. It's about the defense.
Sure you can run both Williams and Gay out there as your two forwards but the problem comes on the defensive end.
You have to make a choice either you:
1.) force Cousins to have to guard a harder player than he might have had to guard if JT was out there along-side him.
2.) have Cousins guard the 'eaiser' big (Jordan/Robin Lopez/KG) and put Williams in a defensive mismatch having to guard players with a lot of height/length on him.
If we had a typical PF with PF size/length/defense you'd see the following match-ups more times than not:
Clippers: Griffin guarded by PF, Jordan guarded by Cousins
Grizzlies: Randolph guarded by PF, Gasol guarded by Cousins
Trailblazers: Aldridge guarded by PF, Lopez guarded by Cousins
These are just a few examples of the choices that you'll have to make if you run both Gay and Williams at the two forward spots. I don't really want to see Cousins having to guard Griffin, Randolph, or Aldridge but if he doesn't that means that one of Williams/Gay will, which puts them at a severe disadvantage.
Playing JT in the starting line-up provides 3 advantages. First it allows us greater flexibility when it comes to defensive assignments, second it allows him to maximize his role as a defender/rebounder as he doesn't need a lot of shots to be effective, and third it puts a scorer back on the bench in Williams/Gay.
I have no idea how it will play out, but for these reasons I do think that continuing to start JT makes the most sense. As has been discussed quite a bit, JT is a great 3rd big, and I would love to play him that way, but we need to find a better starting PF to take his spot before he gets relegated to the bench.
It's an exciting thought to think of IT/Ben/Gay/Williams/Cousins in the starting line-up as that line-up has a ton of speed/quickness/athleticism at all 5 positions, but as exciting is it is, I'm not certain it's a long-term winning strategy especially against winning teams, and even more so against winning teams come play-off time.
Also, I should mention I don't necessarily agree with Arkitect's conclusion that we'll have to trade Williams if we don't start him, but I'd certainly like to continue to play Williams a lot of minutes and see if he continues to produce at a high level.