I think that if you look at the really strong teams in PB they have:
1) Been around under consistent strong management for a long time, often dating back to CSN.
2) Been built around a few superstars.
3) Been active but not necessarily unfair traders.

Many studs of today were late first, or even later, rookie picks (Berkman, Giles,). Many studs didn't blossom right away, or were seen as disappointments (Sosa,Green,Ramirez,B.Williams) which led to them changing hands early in their careers. Some were hurt at one point and changed hands when a manager either didn't want to wait a year or thought the guy was aging & starting to fall apart (Bonds,Schilling,Johnson,Walker). Many were vailable in the FA at some point (Nevin,Vidro,Vizquel).
So don't conclude that all strong teams have been built by the "three card monty". Good drafting, trading, decisions and bets on future development and, most of all, luck were involved.