Basically, since I'm too poor to afford XL engines, I swapped the engines from my already slow Shadow Hawk (went from 80 to 70) and my not-zippy-enough Jenner. I think it improves both mechs although I still think 2/3rds of tonnage == engine is silly.
Or maybe I was lucky and got on good teams when I tried out the new builds. Could go either way.
Now... if I can somehow fit the old Jenner engine in my Raven, and put the even tinier Raven engine in the Shadow Hawk... can I make a Shadow Hawk build with more firepower than the stock Atlas?
... that is a trick question. It already has more firepower than the stock Atlas. I don't know how they make the trial mechs that bad but wow are they bad.