I haven't heard a single thing other teams have learned from the other interviews that had anything to do with future success. Do you have a list? Not just a team's saying we learned a lot but what teams actually learned from guys they did not hire in the interview process that actually led to results on the field?
I interviewed a ton of people over my career and at the beginning I interviewed everyone that applied, by the end I'd narrow 100 resumes down to 3 or 4 no problem and never felt like I missed anything doing it that way.
So overblown the interview a lot of people angle, has no real benefit if you have top candidates willing to come.
You have to be a pretty incompetent organization to need to interview 10 guys, what kind of screening process are you failing at?