One thing I will say is that 10-15 for Chauvin is probably more "punishing" than a normal person recieving this sentence as he has to spend it all in solitary in all likelyhood.
Aren't there prisons/prison modules for "low level/low security" offenders? The kinds that are fairly chill (by prison standards) and have people in jail for stuff like political corruption, low level drug dealing, and the kinds of people that are well on their track to reinsertation? (and where beating up Chauvin would set them back by an amount that they can't afford, so they'll restrict themselves).
Like I can think of a ton of other criminals who would be high profile and at similar risks, like say corrupt polticians, famous people and stuff.
To be honest a 10-15 year solitary punishment should qualify as "cruel and unusual punishment".