The last two games you might be right, but for most of the season their first two off the bench Clark and Stokes have been excellent in their roles. The starters are all scorers, so defensive stars on the bench go well with whoever else is in the game. Beyond those two if they can get Williams back they can field a great 8 player rotation, with 5 starters as good as anybody, and at least compared to off the bench a very good big (Stokes), wing (Clark) and guard (Williams).Aces have gotten 2...count em 2...points off the bench the last 2 games combined. That does not cut it, no matter how good your starters are. Clark had to start one of those games, and she did score some that game. How long can Williams milk this sore back thing? The season is half over. She needs to get on the court and help provide a bit more scoring punch from the reserves.
If all those players are healthy, that is probably about as far as Becky goes in the rotation in big games, without a weak link for their role among them. Williams of course could fill the offensive spark off the bench, and Bell has improved enough that she might be a pretty decent 9th player when Williams returns and doesn't really hurt them much if any as their 8th player now.
I think most opposing coaches might not consider the Aces bench super deep, but because of how good the first two are (three with Williams) I think they would consider the Aces bench an asset, not a liability.