That seems like it would work, but how would they portion out the final ownership? Maybe the person who bid the most could get the most shares?

Rich people can always find a common ground and negotiate deals among themselves, its what they do every day.

As a rich person I’d rather get 30% of tiktok with 99% certainty by committing 30% of capital needed, rather than 100% of tiktok with 30% certainty and committing 100% of capital needed.