To some extent the more rules and oversight you put in, the more you chase out any "honest participants". I've seen it personally in federal contracting, the only participants who can get through the bidding process are the exact companies (like the big 5) who you don't want doing your project. The oversight and complexity of the bidding process chases out anyone who is not willing to spend half their time on meetings and contract overhead if that's what the customer is willing to pay for. It's the dead-sea effect but for contracting, if you chase out the good participants and then tighten the noose, you will just end up with worse and worse participant quality on average every time you repeat the process.
There's no easy answer.