Great post...
I feel Noel will add most to our starting lineup. When allowed to actually play daily he is developing an offense game, he rebounds, and defends well. He is able to cover 3's,4's, and 5's, he's mobile. He'll give Horford a chance to play PF, his position of choice. He's not a big, slow lumbering type of Center. If you want to go small, Horford slides to the center position.
He comes from the Boston area, I think he may want to sign and remain here. He's certainly not a max player.
Don't count out Cauley-Stien, I'm able to watch him often, he's playing behind 2 veteran bigs, one being Cousins. Every time he get a chance to play, he contributes, and plays solid D, again he can defend 3 through 5. Again he's very mobil, he runs the floor very well...And he's on a rookie contract.
Both are young and have upside remaining. They fit on this team better than an older, slower, veteran center, who will be retired in 2-3 years. Let's get a big we can develop, the C's aren't a contender for anything but a first round out.