So, how long would you say it took to build your team to play that style?
After messing up a scrimmage, ruining game shape, and setting myself on a course for relegation, I decided to sell my more expensive players and buy a new squad for D2. After considering it for a couple of days I decided to attempt to put together a squad to play fcp.
Since they sold on 7/7 I must have put them the first 5 players up for sale on your Independence Day. Within 5 days I'd replaced them. 4 weeks later I'd bought 3 more for the start of the season. I kept only 3 players from my D1 squad. My main player, and 2 scrubs. In D2 even the scrubs got among the steals and blocks.
During season 32 I added two more players, a starting point guard (prior to signing him my starting SF had the highest PA on my team with 13) and a backup C.
I've bought 3 players since promoting. 2 PGs and a PF who can play SF.
In essence though, the answer to your question really is, my first squad took me only about 4 weeks. And since then its just been an ongoing thing.
My current squad consists of 6 PGs, 1 SF, 5 PFs, and a C, though most of them are capable of playing multiple positions.
I apologise for the long ramble, but I felt the answer needed a bit more than just saying "4 weeks!"