Instead of (or in addition to) the point WP/SP system, I suggest using the final win loss record of your assigned alliances to break ties. Wins with lower ranked teams are favored over wins with another higher place team. Its just a rough idea at this point. Anyone else like the general idea?
This is what good scouting is for. Also, it should be noted that the more skill based this program becomes, the more and more likely it is that the popularity will drop off as teams cannot keep up, and simply quit.
EDIT: Forgot TRSPs, which was designed by the community in the Sack Attack season by community members.
link to the thread: https://vexforum.com/t/sp-ranking-system-ideas/22614/1
The concept is essentially what you have described, with some additions, such as factoring in your opponent.
VexDB automatically calculates TRSPs for every event on RobotEvents. Example: http://vex.us.nallen.me/events/view/RE-VRC-15-1575?t=rankings.