He'd most certainly fill a need at the big man position, though we still don't know what we have in Arnett Moultrie due to Doug Collins being inpatient and not giving him enough minutes. Mason Plumlee, brother of Miles Plumlee who currently plays for the Indiana Pacers would bring a huge explosion to this Sixers offense regardless of who the head coach is. The guy's an athletic freak and his dunks alone would send a shock throughout the whole arena. It seems Kelly Olynyk would be nothing more than another version of Spencer Hawes at center and really wouldn't make much sense. Does it really makes sense to have an almost identical copy of a player you already have?
Plumlee has averaged 17.1 Points Per Game, 9.9 Rebounds, and 1.4 in Blocks. Plenty that can be worked on, but there's no denying this guy will kill it on the offensive side of the ball. He has the physical tools, he has an NBA Ready body at 6' 11.5" at 240 pounds, freakish athlete and jumper for his frame and position, runs the floor well with great energy and making strong finishes at the rim. With Plumlee, they could easily plug him in at Center and plug Moultrie in at power forward. Either way he gives you versatility at power forward and center.
That would make a good frontcourt in my eyes. He relies heavily on athleticism and is excellent at rebounding the ball. Which is what the Sixers may need, I can't imagine having to rely on Hawes to play defense and collect rebounds. Makes me kind of miss Nikola Vucevic on the night he grabbed for eighteen rebounds while Hawes only grabbed for one. With Plumlee, I doubt he would get beat out like that, but you need more than athleticism. Yes, athleticism is a nice tool to have but you will need to learn techniques to succeed in this league.
I also considered Cody Zeller as another option at big man as well. Yes, he's scouted to be better and have a more successful career than both his brothers, and he's offensively gifted. Same goes for Olynyk, but they won't cut it on defense. Olynyk is more of a replica of Hawes than Zeller is. Then again, the problem with Plumlee is, he's not a threat in terms of a shooter. He mostly get's his points from inside under the bucket and dunking. But if you're to draft a big man with physicality, explosiveness, and athleticism, Plumlee may be your guy at No. 11.