I reread the Cadia rules, I completely missed the "pick lowest of two" leadership rule. Now I see why you said it isn't an easy fleet.
I don't fancy battlefleet armageddon. The extra battlecruisers sound nice but I really want to take swords as escorts, as they can stay abeam. However, I don't fancy taking marines and swords have to be RSVs.
Would the extra NCs really help with my ranged attacks. They do seem pretty random. However, I'm a Guard player at heart, so strong yet inaccurate blasts is kind of my thing. I'm just concerned that I won't have enough torpedoes to obliterate things up close. It would mean that the lunars don't need to reload, although all of my ordnance would be on two ships.
I can't actually decide if I want the Apocalypse. I looks like a nice model but seems to lack range for a battleship. The Retribution looks nice, although not very powerful. The Emperor seems to be what most people take, although I would probably have to drop the dictators. Those points could go on a battlecruiser upgrade.
So many decisions. This makes thinking about 40k lists seem easy, and there are only 5 capital ships to think about.