That's...difficult to say. I'm betting the Eldar have the advantage in technology and power output. So on a ship for ship basis I think the Eldar win most fights. Planetary engagements will almost go entirely to the Eldar. Hell, the Klingons would LOVE to have fights against certain Eldar forces (Close combat weapons everywhere!!!)
What's really going to screw with the Feddies are the Psykers. Because the closest they've got are the Betazeds...and they aren't up to what the Eldar can do. Maybe the 'zeds can offensively strike at the Eldar or invade their minds, but that's...iffy. I'm pretty sure every Eldar has some resistance.
What's really going to screw with the Feddies are the Psykers. Because the closest they've got are the Betazeds...and they aren't up to what the Eldar can do. Maybe the 'zeds can offensively strike at the Eldar or invade their minds, but that's...iffy. I'm pretty sure every Eldar has some resistance.