Tim presented a well-thought-out alternative to totally contracting leagues (which I advocated below but which would be unbelievably difficult to sell).
In Fred's comments we see the problem.
The folks who have good teams do not wish to give any ground at all in building competition. This is understandable but shortsighted.
Much of the effort of building teams is really luck.
Actually the unowned teams would not be such a huge problem if some mechanism for freeing the players for fair and equitable trades could be devised.

How about a panel of owners to review trades with unowned teams and those trades could only be open for a few weeks in the dead of winter when not much is happening in the leagues?

Dave N