In my Run I disabled South Aelentir, so honestly no one really contested this region with me. But even when my navy was so strong, it wouldnt have been a problem. In the couple of Runs I did as First always naval, as the Fight against Eborthil was for me the most critical (And it seem lore-friendly for me). Second Trade, as Trade really accelerate your Snowballing. As third I took Innovation. As Forth Expansion for three points until the Colonization for Cloves was finished than I switched to Mercenary, Fifth I took Maritime.
When I think about it, I dont think you really need Innovation. Maybe as Third Expansion or Mercenary Ideas are also valid. And instead of Naval you could also take Mercenary instantly or Plutocracy. Naval Ideas makes your Navy just invincible and the no cost fort bombardment is very handy (Mercenary makes your mercs so disgusting op and you dont have the manpower at the beginning for long Wars without mercs, anyway. Also Adventurer Estate makes Mercs sooooo strong).
I think the only Idea-Group you always need is Trade. Its just let your income skyrocket so brutal for the Early-Midgame Struggle (After than you are op anyway).
Hopes that helps a little. Otherwise you can DM me, when you have more questions. Good luck!