I look at it this way in terms of the core rotation:
Guards: White, Holiday, Pritchard [Springer]
Wings: Tatum, Brown, Hauser [Walsh]
Bigs: Porzingis, Horford, Kornet [Queta]
If you are 3 deep in each of these categories, that is pretty good. I see our wing group as probably the best in the league. Right now, our 3rd big is Kornet, but sometimes it is Queta. Springer, Walsh, and Queta are all fine as the 4th in line, you don't expect them to play in the playoffs or any other meaningful minutes. I guess this is kind of a 1st World problem but I feel the weakest spot is 3rd big. We are very solid through 8 though, when everyone is healthy, so hard to complain. And Kornet isn't horrible as the 3rd big. Definitely serviceable.
Any concern I have at the wing is due to Hauser showing some durability issues. If he is not up to snuff, then yes, the 3rd wing role could be of some concern. But if he plays at the level he has for the prior two seasons, then I am not worried about the wing group. Walsh as the 3rd wing would be concerning but the same would be true if Pritchard got hurt and it was Springer who had to be the 3rd guard. Our top bigs are the most likely to miss games also so the 4th and 5th bigs get called on more often than the 4th guard or 4th wing.