I never build a navy on legendary because I feel like I can't afford it. In the early game I try to keep my income for armies and upgrading my cities. That works quite fine up to the point where the remaining clans are naturally hostile towards me and most of them end up declaring war on me and then lots of my harbors get blockaded which fries my income.

However, it doesn't really fry it to a point where I can't maintain my armies anymore, but I certainly can't build a big enough navy to deal with the constant supply of navy stacks the enemy shits out without bankrupting myself.

So I was wondering, do any of you actually build and maintain strong navies in legendary campaigns or is it just not worth it? I'd love to dominate the seas to prevent my harbors getting fucked but I can't seem to find the income for it.

I've had situations where I would be making 4k per turn and then start building a navy. But then the AI blockades 3-4 harbors in a single turn switch and suddenly my whole income is in shambles making it impossible to further build my navy to defeat the AI death stacks. Usually at that point I'd just end up deleting the navy I did build to free up income again.