I suspect we agree here more than you think, Jay.
I'm not making light of the coaching that occurs leading up to the event, which is important, but the coach's role during the event itself is near zero.
Setting the lineup is trivial and no number of "let's go" comments makes much difference. Fundamentals can't ever be fixed on the fly and any suggestion that players are making mid-match tactical adjustments doesn't jive with anything I've ever seen in countless Mosconi Cups attended.
Yes, it shouldn't have been this lopsided. Perhaps Team USA should have lost 11-6, but Bob Jewett's math said we were huge longshots going in and that's how I saw it, too. I'm not THAT surprised by 11-3, because we so rarely entered any match as the clear favorite.
As for teamwork, Team USA, to Jeremy Jones' credit, looked like a cohesive unit to me, but when the three guys with the most Mosconi experience on Team USA (SVB, Sky, Tyler) all played poorly, no amount of teamwork could have made up for it.
Preparation, which can be greatly influenced by the right coach, makes all the difference, but coaching during the event will always seem trivial to me.