I like the thought of the Draftboard, though I think it would be slightly different. You let everyone in the lowest league have a chance to bid on the set of players for a day or two. They can bid on as many as they want, ranking each (1st, 2nd, etc.). So when the draft happens, it begins with the lowest team on the boards 1st ranking and allocates. Then it continues to give the 1st pick of each team to it as it goes up the lowest league (hitting each X place in every division of that tier). If that first pick has already been taken it continues on to 2nd, 3rd, etc. until it possibly can't allocate a player to a team, if so they just don't get a player that draft. If you want a small draft entry fee, could do that and return it if all the team's ranked players are allocated already.
Rovers: Founded Season 37 Matchday 8
Westerners: Founded Season 40 Matchday 0
Elephants: Founded Season 46 Matchday 19