I'm fine with swapping out Morris and Baynes depending on the matchups.
The clear cut top 4 guys are Kyrie, Horford, Tatum, and Brown. The fifth guy really depends on matchups and who has it going .... Smart, Rozier, Baynes, Morris, Theis, sometimes even Larkin.
It's a good situation to be in, really, when you have so many role players who can step in. That's a function of having a really excellent top 4.
Now, just imagine when Gordon Hayward is that 5th guy .....