The manufactured enthusiasm is all baked into the cake. Read comments from people on youtube in MSM videos be they in France, Germany, UK or America, citizens aren't buying the sizzle anymore when it comes to politicians.
Oddly enough, the choice of Vance when juxtaposed to Walz may end up being a difference maker. The guy needs to find a few more jokes from time to time, just a bit more smile to put some of the touchy-feely voters at ease, but he is an intelligent and competent guy no question. I have surmised that he understands human nature based on how he interacts with different interviewers that I have seen, he understands his audience, not always easy to do even for politicians.
As it were, in his debate against Walz, I wouldn't wager against a man from modest beginnings and adversity who ended up graduating from Yale losing by any measurable metric. I relate to such people though I didn't reach the esteemed reputation of Yale Grad.
You combine street smarts with life challenges and overcoming them and you will find a man who enters the arena with all of his bases covered. In short, he will out-study Walz.
If Vance can add 2-3 points to the Trump ticket in the RustBelt, he will have accomplished his objective.