Trying to trade players to "actual teams" is VERY, VERY hard (EX: If I have Tettleton as a DET player, I can only trade him to BAL, severely limiting my options).
I went ahead and allowed each franchise a SINGLE TRADE allowing movement of players irrespective of their actual teams. This will allow a small amount of flexibility, while maintaining the overall idea of the league. Hopefully this, combined with the idea that non-draft team players are ALWAYS available, will give GMs a bit more ammunition to dig out of bad drafts, bad cards, etc.