Plus Holmes operates best where Domas is anchored. Have you seen a push shot from him from an area of the court that is not in the paint area, near the free throw line? It's not going to work unless Domas' improves his outside shooting and camps out on the perimeter or Holmes morphs into something that he's not.
If Holmes is still on this roster to start the season I think other than for very, very short stretches against specific matchups you won't see him share the court with Sabonis. He'll be a backup, energy big and spot starter when/if Sabonis misses games. He's been very good in that role in the past, but ideally you'd see him packaged with Barnes for some wing help rather than keep him as a luxury off the bench and risk losing HB for nothing next offseason.