i'd wager you wouldn't have 5000 potential vendors once effective competition and smaller deal sizes squeezes out excess profit/graft. but from my experience with state procurement processes, the initial weed-out phase seems highly automatable, leaving a much more manageable fraction of candidates to consider manually.

also, transparency rules should be rigorous enough to illuminate all ultimate beneficiaries (through shell companies and subcontractors) so that larry, his brother darryl, and his other brother darryl can't artificially muddy competitiveness and undermine fairness.