Jesus, all he said was he has the tools. Which he does. Are you disagreeing with that?
Sheahan doesn't really have any specific weaknesses in his game that you can point to and say that that is something he should work on. His weaknesses are more broad and abstract. He needs consistency and to be able to put it all together. Other than that, he's pretty good at everything... Defense, passing, shot, strength, skating, speed, puck protection, board play, etc.
It's not like some players where you can pick out a specific weakness. For example, Nyquist is sometimes weak on the puck and isn't the best on the boards. Tatar is prone to bad giveaways and is under-sized. Pulkkinen is an average skater and is bad along the boards. Sheahan doesn't really have anything specific you can point to and say "This will probably hold him back." He has everything.