^ IT is a slasher. Similar to CAVS approach, they should surround IT with "good shooters", and maybe a big with good hands (Horford and Olynyk are already good -- if they can get someone more dominant inside). I actually think someone like Javale will do well, when IT draws the defense, and dishes it inside.
Whoever Celts get, they should do their part on D. That's who they are.