I think there is already a random map generator, it's the random maps category    I think there is already a macedonian campaign someone made floating out there. I know @Vantha has been getting all the coding stuff in place for a new tutorial that would be exactly this except I think it'll have four scenarios.   I think all the features you requested @lilypoppy are in the works, but if you wanted to get started on your own campaign it wouldn't be too difficult to start, write out your story, start making the maps. When the rest of the features get added there may be some light scripting to do but then it'll be ready!

Would a random map generator be possible? Or a mod maker?

The battle of Cannae is 2241 years old! The anniversary passed three days ago on August 2, 2026. To mark the occasion, I wanted to share an excellent recent documentary on the battle by the channel Invicta, featuring the brilliant Dr. Adrian Goldsworthy as a guest.  

There is also https://gitea.wildfiregames.com/0ad/0ad/issues/8964

Something like this is planned iirc, but the Atlas is built off of some very hardcoded software, and needs a complete redesign in order to add new features. Both things are in the works though! https://gitea.wildfiregames.com/0ad/0ad/pulls/7803   Objectives and events should be in the next release https://gitea.wildfiregames.com/0ad/0ad/pulls/7785/files, dialogues as well https://gitea.wildfiregames.com/0ad/0ad/pulls/8614, and as for the others, those are just trigger scripts (like your first point). This is technically planned, though it probably won't be in the game until R30. However, if more players push for it, then maybe it can be in R29, that's up to the WFG team (of which I am not yet a member). You're 100% right about these, and as you can see, they should be in the game soon-ish. Until then, I hope to see you around the Forums more often, and maybe even creating a few scenarios (triggers really aren't hard once you learn how they work).