According to the eye test, against all but the smallest teams I think the starting lineup of Kemba, Brown, Tatum, Theis, Thompson is the right lineup.
It worked great yesterday, but Theis/Thompson was a terrible at the start of the season. Maybe Tristan Thompson has found its footing, I'm just not jumping on that ship (yet). Daniel Theis was almost exclusively playing PF against Atlanta and he did really well. He's a solid allround player who needs a 'small' role to excel.
I'm always looking at combinations. For example Walker/Pritchard is a very bad combo (-18 Net Rating in 55 minutes), while Pritchard/Smart is a good combo (+7 NR, 115 mins). We also see that the second line-ups with Tatum, Pritchard and Timelord have done very well (+23 NR, 117 mins).
An interesting combo is Ojeleye/Theis (+13 NR, 224 mins), which for some reason does brilliantly defensively each year. However the most intriguing combo might be Theis/Timelord which has the highest net rating (+30 NR, 47 mins), excluding a couple of very limited Tacko Fall appearances. I'm not sure whether Timelord should start, but he definitely deserves a minutes increase over Thompson.
Looking at how all these line-up combinations have done so far, it really stands out that Carsen Edwards, Javonte Green and Grant Williams should not be playing any minutes. Especially together: Green/G.Williams (-27 NR, 75 mins)!
On the other hand the stats have been really kind to Jeff Teague. Maybe he's not as bad as he looks? His line-ups are slow paced, but have few turnovers. And the guy that really draws the attention is Aaron Nesmith. It looks like everybody is profiting from his presence.
Conclusion for now:
Start: Walker/Brown/Tatum/Theis/Thompson
1st subs: Smart+R.Williams for Tatum+Thompson => Walker/Smart/Brown/Theis/R.Williams
2nd subs: Pritchard+Nesmith+Tatum for Walker+Brown+Theis => Pritchard/Smart/Nesmith/Tatum/R.Williams
3rd subs: Walker+Brown+Ojeleye+Theis for Pritchard+Smart+Nesmith+R.Williams => Walker/Brown/Tatum/Ojeleye/Theis
Play Teague when Walker sits in back-to-backs (great idea by Liam by the way to let Walker play the second game, when other guys might be tired) and let Ojeleye fill in minutes (to play alongside Theis as much as possible) when other guys aren't available. I'm still not convinced that Thompson is an integral part of the team, but he needs a rim protector/help defender next to him so that's why he's starting with Theis.
Another idea could be starting Walker/Brown/Nesmith/Tatum/R.Williams and use a main bench unit of Pritchard/Smart/Tatum/Ojeleye/Theis. Anyway in some weird way Thompson and Ojeleye are each other's main competition for minutes.
Roughly you can categorize our players in the groups below, where you try to make line-ups consisting of 1 player of each group, while Tatum and Smart are so versatile that they can fill in other roles as well.
Play initiator: Walker/Pritchard (Teague, Waters)
Second ball handler: Tatum/Smart (Edwards)
Offbal scorer: Brown/Nesmith (Langford)
Hustle guy: Thompson/Ojeleye (G.Williams, Green)
Rim protector: Theis/R.Williams (Fall)