You didn't finish the sentence: "It's a massive incentive to do both..." in the form of a single company over the liability limit.

The obvious hack is to slice the company into (company size)/(liability limit) pieces, but while typing up my complaints about how easy that is, it occurred to me that we have anti-trust, anti-racketeering, and anti-price-fixing laws in place that are basically solving the same problem, so maybe it could work after all with a sufficiently clever law.