I saw an article that was trying to find the "right way" to use Kuzma (making lemonade as he says...). It was basically focused on Kuzma at PF; so Giannis' backup. The skillsets are pretty similar (though a large gap in the quality of those skillsets) and advocated that the two shouldn't be on the court at the same time. Though in a small-ball config with Giannis at C, it should still work. Also using Kuzma in a pick-n-roll role helps because it forces his defender to be up on him and not sagging off to play a soft zone.
So basically, if you have Kuzma in the game when Giannis isn't and have a few minutes of the game with some overlap and limit the SF role for Kuzma (where his lack of 3PT shooting hurts), we would maximize K's strengths (and minimize his minutes).