I think Astute does trump Lunge - with the action failing, the wounds never exist in the first place to be unpreventable.

Yes, Astute would trump Lunge, as the Virtue pretty much says "that action you took has zero effect," meaning Lunge never gets the opportunity to inflict Wounds, thus the "cannot avoid or prevent" language in Lunge's discreption is moot.

This is based in part by an answer from Michael Curry a while back about whether the Bash Maneuver would work against Lunge, in which Mike replied that the wording on Beat and Lunge were very specific; ultimately Bash stops the Wounds from occuring in the first place, thus the "cannot avoid or prevent" language for Lunge doesn't count against Bash, and in fact makes Bash one of the few ways to mitigate the effect of a Lunge.

Edit: Had put Beat (1e Knack) instead of Bash (2e Manuever).