Yeah I'm not really sure how to evaluate Giles on the defensive end. He seemed ok in the Feb-March stint where he was starting and getting consistent run, but the numbers didn't back that up. And really in the rest of his career, his playing time has been jostled around so much it's hard to get a good read on him. Offensively though, there's been more than enough flashes that shows he can be a starting caliber player.
I do think that's a big issue with Bagley as well. He hasn't been good at all defensively, but we have yet to get like a good 2 month stretch where he's on the court for 30+ minutes to evaluate. It's always been him coming back from injury or coming off the bench.
Regardless though, I clearing the decks for Giles to get playing time would be the way to keep him around. I imagine wherever he goes, he's looking at a spot to get real playing time to cash out in 2021 with a bigger pay-day. If he loves Sacramento the way he says he does and Holmes, Bjelica etc are gone, I'd believe he'd be back.