It really does come down to what set of rules you want to play by. You can come up with situations where the Hades wins (nobody maneuvers, table stats only, Erebus out of pulse cannon range, Erebus power grid nerfed down to FS1 tech levels) but they don't really reflect the capabilities of the combatants - it's kind of like saying 'Arleigh Burke vs. Bismarck, daylight, 1 mile range'.
The Hades is a really really powerful ship for its timeframe, but it doesn't have the capabilities required to play in the same ballpark as the Erebus. They're operating in two very different tactical contexts. Which is pretty cool! It's neat that the BP ship depends on the stuff BP tends to care about - complex systems, electronic warfare, active armor, maneuvering, sophisticated AI, air wing - and the Hades depends on the stuff traditional FS tends to care about, like huge beams and loads of HP.