I remember having plans for something similar exactly one year ago, granted the situations and type of alliances were different. I wish you good luck with this. As advice from someone who tried it before.. the major flaw you can have is human lack of commitment, independently of how awesome the system is. Unless you somehow work a simplified system to get it working, though it might be hard considering it's several alliances you'll be coordinating, you'll need a very dedicated and reliable team to run it, otherwise it will fail.
Again, good luck
EDIT: Well there are a few more things in your favour, so the odds are way better