You can adjust the auction terms to try to avoid bad outcomes. A) bid out smaller alocations to allow more networks B) require a deployment plan to bid, and progress on the plan to keep the allocation C) some equitable way to periodically rebid in absence of abandoned spectrum D) some sort of open access provisions (maybe spring this on the market after it's largely built out)

Of course, some of that requires a competetent regulator with clear authority, as well as not too much corruption and reasonably swift court systems to handle disputes. But a point in time, single payment auction works better with those things too.