Fans shouldn't get hung up on position labels. They are almost meaningless.
However, it allows us to talk about what a player does on the court. A lot of players can play more than one position.
I agree to an extent. He's not the PF I'd like but starting him alongside KD, Booker, Tyus, and Richards would be fine. I'd prefer a more traditional PF who can also play small ball Center like a Dario Saric, Amare, Diaw type of player. I say those 3 because Suns fans should be familiar with them and they all brought different things to the table as well. Butler isn't a traditional PF but neither is Ryan Dunn yet here we are starting Dunn so quibbling over Butler's position doesn't make sense at this point.
All that said I'm not excited about the prospect of re-signing Butler to run with KD for the next 2 years though so I'd rather stay away from a deal for him that isn't a straight swap of KD for Butler, even if we don't receive picks in return. It would allow us to free up finances sooner and remove the tumor that is KD from this team. Even if Butler is extended I'd be in favor simply because he plays harder than KD and has been the leader on more successful teams as well. I think that would help right the ship here but we'd still be off course but to a lesser degree.