My key point is that there is a range of possible outcomes, from...

My key point is that there is a range of possible outcomes, from likely outcomes, to less likely outcomes, and thus a spectrum of valuations (from less likely to more likely). Of course, in principle this is always the case, and we often account for this by estimating what we believe to be a most likely (or base case) and then applying a "margin of safety".

However, my strong sense is that in this sort of situation, where the probable variance is quite acute, applying a "margin of safety" is too arbitrary. As such talking about a "base case" valuation alone is almost meaningless.

Just my opinion.