I think this point has been stressed enough times, but the above statement is just wrong.
Our starting 5, which will also play the bulk of minutes is Fox, Huerter, Keegan, Barnes, and Domas. One is free to dislike this starting 5, and think that we should have someone else play the 3, but it's just not true that we are relying on Kessler and Slawson.
Now, an argument could be made that instead of bringing back Barnes, Monte could have gotten a more natural 3, and moved Keegan to 4. Without knowing what was available, at what price, what the coaching staff thinks of replacing Barnes' production on and off the court, and their thoughts on moving Keegan to 4, it is impossible to say that a better move was available.
The backup 3 minutes will be shared by Kessler, and we might also see more of Kevin/Monk there if we play 3 guard lineups. I honestly don't expect Cole-Slaw to get lots of minutes during the regular season. So, again, you can dislike this arrangement, but let's acknowledge the likely minutes distribution. Else, the entire discussion becomes meaningless.