Do you really believe that most of the great teams acquired these players by skulduggery ? It is very hard to trade for truly great players and when you do you usually need to give a lot for them.

I have Bonds on one of my good teams and acquired him in a trade a few years ago. I traded for him the week after it was announced that he was done for the year with season ending elbow surgery at 35, and I offered a lot of talent for him. If he had gone downhill and never bounced back this would've been a different story. On that team I acquired ARod in the CSN days by trading Albert Belle and another promising shortstop, Derek Jeter, for him. That trade helped the other team towards a championship, should it really be against the rules ?

This would be very hard to manage and require 20-20 foresight, not hindsight. In my opinion, the good teams are predominantly where they are because they made the right call on 30+ players career direction: trading the guys who eventually went downhill, getting the guys who bounced back. You're going to regulate that ? Good luck.

The other thing good teams do is make better use of their rookie picks. By drafting players who develop more often into useful players (despite disadvantageous draft position) the good teams can then be in a good position to trade. Luck plays a HUGE role in this.