After watching a whole lot of Hawks games over the years, I believe that one of the hawks major problems is that they have 3 Power Forwards as starters. lets look at each of the 3 players.

Marvin Williams: Criticize him all you want, but he is a very good defender. I have yet to see a player that has abused Marvin on the offensive side besides maybe Durant( and he abuses everyone). Marvin's key weakness is his ball handling and inability to drive to the basket without  turning the ball over. This I believe is because although he can guard 3's very well because of his quick feet, the weaknesses noted above  limits his  offense.

If Marvin was to play the 4, he would not have to go by quick players at the 3 but rather slower and stronger players at the 4. He has the lower and upper body strength to bang with the big boys down low both on the offense and defense. Also, because of his rather clumsy ball handling skills, he would not have to do a lot of ball handling at the perimeter. All he would need to work on, will be his low post moves. With his naturally soft hands , this should not be a big problem. 

Josh Smith: Josh has better vision  and ball handling skills for the 3 position than Marvin . However, his poor jump shot and lack of lateral quickness limits his ability to play the 3. He has greatly improved his low post moves so if he would stick in the low post, he would be a very good 4. 

Al Horford: Would Al be a better 4 than 5? Would Al make the all star team if he was a 4. How would he fare against 4 's that play outside the post e.g. Lewis, Garnett, Bosh etc.? I really don't know. i think Al would make a good 4 . However, one area I think he would struggle would be on the offense. Al is kind of mechanical when trying to get by players. This might not limit him against centers, but I think he would struggle against 4's on offence.  Besides that, i think he would make a very good power forward. Not sure if he would be an All Star at this time of his career. For Al to be an All Star at the 4 this season, he would have to beat out one of the following players- Bosh,Boozer and Garnett. I dont think he is better than any of them.

In terms of height and weight, all 3 players are almost the same  and they all have stats stats that are closer to the average Power Forward. 

Josh Smith  6-9 240

Al Horford   6-9 245

Marvin Williams 6-9 240 

What do you think ? Who would be the best Power Forward?