I don't think increasing the target limit is a silver bullet. I think it could be a part of a larger change to the "Outnumbered" effect, if it got a complete overhaul.
Linking target limit to the ruins/bloodlust strikes me as a very bad idea. I can only see whichever server is dominating at the time, sending people to claim it, and run big zerg with + target limit. While the majority of players doesn't even know why/how, as most doesn't bother to find out or learn.