"Those /share values are, as you well know, insanely disingenuous (from the standpoint of...well, reality, anyways)."
I wouldn't call "those/share values" "insanely disingenuous" whatever that means. They are obviously optimistic, but they were backed up by assumptions or whatever partial data we have so far.
There's nothing wrong to be a bit optimistic! It's natural for sellers to be optimistic with the price and buyer to hold the opposite view. I'm sure Teck or whoever the buyer maybe will try to get SC for a lower asking price and that's fine. That's when you start negotiating and come to a price both sides can accept.
Needless to say at this point, without all the data, we are all speculating based on incomplete data, and yes, we may be a bit optimistic but I wouldn't call that "insanely" so! JMO GLTA!