"However, artillery being captured, turned around in the heat of battle, and starting firing on the troops of its previous owners? Unlikely." That's probably right (can't remember any counterexample), but the same argument could be applied to ships, and that's going to be in the game now. It’s like proposing removing the building of towers because that didn’t happen while a battle was taking place meters away. It's all a representation of things, numbers and time are shrunk with respect to what in reality would have been, it seems to me that completely removing something that happened just because it didn’t happen in the same battle is the wrong call. Capture times would have kind of prevented turning things around in the heat of battle, and if not, a “use cooldown” could be implemented, one being able just to move the piece in the meantime. Edit: I think something like that was proposed for towers and fortresses, to avoid turning them around fast, although more from a gameplay perspective than a realistic one. For ships it would also make sense to have a use cooldown.

Here the opinion of Nescio:  

If one's civilisation has the arsenal, then it should be assumed that there would be engineers in the army that know how to handle equipment, it makes no sense to remove something that happened in reality because there’s not a differentiated engineer unit in the game. I’d even argue that even some things like rams could have been used by anyone. Without the arsenal maybe one could capture and move, but not use (the Rhodians captured very complex siege equipment from the Macedonians, which they sold to finance the Colossus). In reality equipment was even reverse engineered (the Romans used Carthaginian techniques after capturing one of their ships), but this would be too much, so what I mentioned before (having the arsenal) should be a reasonable minimum requirement for using captured equipment, without altering what one’s civilisation can build (which is harder than just using), to make things simple.

I think it is because @Nesciowanted to remove the feature, arguing that siege equipments cannot be used without the engineers/experts necessary.

Hello, Thank you for all this information.