Even if you were going SF I would still do big man skills first. I'd want my players to contribute as much as possible as soon as possible.
He'll contribute more at PG this season than he would at PF or C (or even SF) where I have 6 players better than he will be this season. Plus he'll train faster at PG skills this season, will he not?
Where we differ is that I have a vision of how I want my team to play over the course of several seasons, not simply this year. Hamby is the future.