They could just scale it down if they needed to fit the entire thing there lol, but no, supposedly they decided to crop out Buggy and Doflamingo but keep three guys including Mihawk, two of which we know for an absolute fact completely desired to be PK but had that dream crushed lol but Mihawk apparently didn't.
And that "weird-shaped panel" cope is just weak, it took me 30 seconds to do this lmao, someone professional who is paid could make it look much better, appearance isn't an excuse.
If Mihawk wasn't suppose to be there they could have very easily removed him, but they didn't, instead they decided to keep him alongside Moria and Crocodile, two guys who dream of PK.