Posted it on feedback but i'll put here too.

I think two additions should be make with spies. First: Should have more missions inside City state. We should at least be able to neutrilize governors on it. It would be a way to counter the governor making pressure on your cities loaylty.

The second, should have a special mission to track down your captured spy and you could try to free him/her. Once you capture a skill you should choose where you would put him, the city, or even a particular district. Spying missions could have a chance to find a lead on his/her location and then a special mission to get him back. And when you get a spec ops you could make a special attack on the location to get it back. And if you put it inside a militar build it would be harder to get it back.

Change the spy one location to other could be spy mission too, one you could only perform once in like 15 turns or 20.