[bolingbaker]

I believe there is a solution to your problem. It would be quick, dramatic and effective. This solution probably will sound strange, but the positive & practical effects would be immediate. I looked at the Greek Affairs website for U-Mass-Amherst which, as I read the thread, appears to be the school in question. You seem to have a mixture of local fraternities, plus some nationals that - as you describe them - are lethargic, and mired in poor leadership, no direction, etc.
The answer is to immediately contact the major nationals fraternities known to be very aggressive in rush and very skilled in expansion, and ask them to come onto campus as soon as possible. You said there are no rules; that works out perfectly. It's free-market Heaven, and the big dogs can establish strong, attractive, positive organizations within one school year. The system will be flooded with new blood and energy, and the older houses will have to scramble to keep up. YOUR chapter will be better, larger, stronger because of the competition and the energy. Right now no one is challenging them. The weak and unwilling to compete will die, pruning the tree and making it stronger. I don't buy the "weakest link of the chain" analogy for a fraternity system. If a chain has a weak link, you get a pair of pliers and take it off before it endangers the whole structure. Those chapters offering the best "product" will prosper.
These national are very aggressive, very strong marketers, and are not represented on your campus according to the website: Alpha Tau Omega, Beta Theta Pi, Phi Delta Theta, Pikes (Pi Kappa Alpha), Tau Kappa Epsilon, Sigma Alpha Epsilon and Sigma Chi. Guaranteed to shock the campus and the administration and the existing system. Guaranteed success. There are literally thousands of prospects out there on a campus that size who would never consider joining a fraternity now. The big dogs know how to make big things happen fast.