Sorry, either stadium size matters for everyone or it doesn't matter for anyone. You can't have it where it matters at some places but doesn't matter at others like you first stated. And don't kid yourself, if ISU had a 500,000 capacity stadium and filled it they would be more valuable to any and all conference realignment scenario.
You're being intentionally dense, or at least i hope so.
The quality of our stadium matters to us, and by us i mean our fans, because it improves our gameday experience for our fans.
As far as value to a conference goes though, your stadium size means precisely ****, and that goes for everyone. Your value to the other schools is what matters. Your stadium size doesn't generate revenue for other schools unless you are in a conference that splits gate revenues. What does matter is things like the amount of viewers you bring to any game. If ISU had 500k people in the stadium, but nobody else tuned in to watch us on tv (for some reason our fans
hated tv watching, this isnt a reasonable scenario), we would bring zero tv value, and thus would just be a sink on the shared tv earnings.