On the contrary, I'd make the rarer siege units (catapults, bolt shooters) capturable so those civs lacking them can use them.

Mod update: Added detailed description in the first post. Technologies for researching Phase 2 and 3 gradually increase the characteristics of units(resource gathering speed, attack, defense, etc.). CivCenters can be build closer together. The minimum distance has been reduced from 200 to 120. Rebalancing of siege units.  The Arsenal is available from phase 1, but it takes much longer to build. Rams are available from phase 1, but they take longer to recruit and have lower stats.  When moving to the next phase, the construction time for the Arsenal is reduced, and the stats of the Rams are increased. Capture is only possible for Rams, as these units are available to all factions. Other siege units on phase 3.

It would honestly be great if it was either an element in options, or a toggle button in-UI in-game (my preference), or both. 

This sounds like just going with what the dictionary states, which is my position, mostly because in general it would be too much work to question what they say, and because things beyond our knowledge were also taken into account. In any case, I find using warją for the fortress a more pressing issue, I don’t think it is good to have repeated words if there are alternatives, all these situations deserve a second look given that @Vantha said “that's the case for some other civs too already”.

I've just realized this was just here at page 3 l didn't remember