Well if that works there would be several things to consider. Putting aside that it's insanely overpowered, there needs to be a way to limit the number of creatures summoned, a way to point where they should be summoned, a way to choose which reserve slot is getting summoned, a way to limit how many times you can summon. The summoned creatures should also count against your leadership total since summoned creatures normally don't, otherwise you'd be able to summon several stacks of the same creature. The number should also be significantly lower than your leadership actually allows for, summoning a full stack of creatures would completely wreck what little balance is still left in the game. It's not a project to be taken lightly.
