Tomasz Adamek should be classified as a cruiserweight.

[pugilisticspecialist]

He never won a proper world title at heavyweight.
He won the IBF at cruiserweight and defended it twice.
He also won the IBO at cruiserweight and defended it once.
His best wins are at cruiserweight and light heavyweight: Cunningham, Briggs(x2), Banks etc.

[gilgamesh]

I would assume they label these guys as the most recent weight class they fought in. If they don't, then yeah I'd agree with you.

[claudevsq]

Normally, we used to rate a retired fighter in the weight class he most fought at, where he won most titles, had the most success etc. That'd be cruiserweight for Adamek, yes, but has he really retired, or is he just inactive atm?

[pugilisticspecialist]

He's 44 years old and his last fight was 2 years and 4 months ago.
Poland is averaging more than 400 COVID deaths per day, I'm pretty sure he's done with the sport.