I originally thought of this feature as an addition to the honour/prestige indices. It's not that I think it would be a silver bullet for all of BM's problems, but I think it would be more relevant than H/P currently are. I also proposed changes to H/P: http://forum.battlemaster.org/index.php/topic,5655.0.html
I also think that it could possibly motivate some lords and dukes to try harder to attract knights to their regions, since doing so would boost their score. Again, it's not a silver bullet, which is why I also proposed some other FR's to hopefully go along with it, and I have a few more ideas that I haven't written down yet.
http://forum.battlemaster.org/index.php/topic,5599.0.html
http://forum.battlemaster.org/index.php/topic,5655.0.html
A lot of people have been attacking the devs for coming up with the glacier experiment to address the low noble density and poor player retention problem, but I'm not seeing a lot of alternatives being put forward. Frankly I think it's easy to attack an idea (and I've criticized the glacier thing) but criticizing without proposing a better idea is just criticizing.
I like your H/P idea, I don't your island stuff. But that has no bearing on this feature request. I see no need for it, thus I see no need for an alternative. The alternative is play the game and figure out for yourself what their political power is.