Fleet phase 2 Executrix enemy capital ship

I was watching a video of a guy winning the Executrix mission in phase 2, his enemy was Mace Windus capital ship, looked quite easy and my ships would be enough for that.
Started my battle and I was against General Kenobi. That's a whole different ball game
Never noticed this before. I've gotten it done before so that must've been against Windus ship.
It's just weird.
So far it's been what, 5-7 Geo Tb:s, I've gotten this mission done twice. is it 50/50 or...