Honestly, I don't think I care too much about the idea that we should have taken a Center because of positional importance. All of us talked endlessly about using a BPA philosophy in regards to the draft.
I'm only upset with not selecting Jonas if he ends up being a better player than Tristan. If Thompson ends up being a superior player, he was the right pick, no questions asked. I also don't subscribe to the idea that it will be harder to find a Center to pair with him. Thompson's very fluid with the ball and moves very well and is more dynamic than the centers you mention whose skill-set he "shares". He just has to work extremely hard on developing a jump-shot. Many players are successfully able to do it, and if the Cavs believe in his work ethic he should be able to develop that type of game as well. There's no real pattern in the league where you need to acquire a certain type of Center a certain type of way. NBA contenders and champions all get their centers from different types of transactions and they get all types of different centers. The key is having quality players in the middle. PF's, C's, back-ups all of which can play team defense, rebound, and control the paint on both ends of the floor.
I still would have taken Jonas because in my opinion we was the BPA, but Chris Grant decided to maybe make the most important decision he will have to make as a General Manager by using the 4th pick to take Tristan Thompson. If he did that because he felt that Thompson will be a better player than Valanciunas, then I can't fault him for it until he's proven wrong.