Physically he seems fit for the HW division. 6’0 while not being extremely tall is nothing to scroff at, and keep in mind this was a time when the heavyweight division wasn’t filled to the brim with genetic freaks yet. While he was only 188 LBS it seemed he preferred this weight, he was known as a fast fighter but was shown to put on mass when necessary(Patterson V Liston 2 when he put on 20(maybe 15?) pounds.) In conclusion, is Floyd more suited towards LHW? Probably. Is he extremely deadly to HWs? Certainly.
I don’t think he could have comfortably made that weight for long. Staying at 175 for the duration of a whole career might have drained him. It’s actually unfortunate that the cruiserweight division wasn’t around in his day because THATS a class he could have dominated
Patterson was really only a SMW when he turned pro, & he bulked up for the express purpose of competing for bigger paydays @ HW. He was absolutely capable of remaining @175 for some time if he really wanted to.
As much as he could've stayed as a light heavyweight, I think that what he did at heavyweight was great enough for us to be thankful that he stayed up there for so long. He was always entertaining and fought on for quite a long time in the pros, Moore, Johannson, Liston, Ali, Ellis, Bonavena, Quarry, Chuvalo, Machen... We lose a lot if we don't see him stay up there. He would've dominated light heavyweight, but the fact that he chose to stay up higher and fight at a level that challenged him says a lot.