As the title mentions, it would be really nice to have a training dummy which behaves similarly to players in terms of stats

We already have a trial dummy which can apply general buffs to you so a dummy which applies battle spirit should be technically possible?
You could add a dummy has effectively the standard vengeance stats.

Alternatively an option for a Heavy vs Normal dummy similar to the skellys (the heavy would have 32k resists and baseline crit resist) would be nice.