"Saying you guessed is prohibited"
You got that right, but just about as idiotic is trying to put everything into a numerical metric. Sometimes just by reading the proposals you can just intuitively tell which offeror knows their stuff and can actually deliver on their technical claims versus which one(s) is/are either barely getting by on technical justification or has/have loads of content that appears to be utter b0ll0cks. "Risk" metrics are supposed to cover this but are often understated and/or ignored up the chain.
===> Anon for obvious reasons, as Rule #1 of Source Selection Club is you Do Not Talk about SSClub, and Rule #2 is... (Note: I've only done SSC for a prime defense/defence OEM choosing major componentry, not an actual gov, but the same rules apply because contracts say so.)