While I understand why there are heavy restrictions, and don't expect anyone but the factions to become wild or nomads, I would like to put forward the statement that the Keepers, at least, aren't pure nomads...they're nomad guards, and leaders among the nomads, from the last time I understood one of their RPs. That leaves a lot of rp space empty, and I would like to see a few independent nomads, real nomads, to fill that space.
Wild, I believe, should not have independents.. I do think they need a whole lot more activity, or more members, and probably both, though. The group is a military organization, and I would expect the leader of the faction to be the leader of -every- wild.
I'm also going to second what kingvaillant just said. The leaders and founders of each faction worked extremely hard to get those factions viable, and just anyone shouldn't be allowed to be a Nomad or a Wild, or Phantom, or Terrorist. There's to much room for abuse.