I don't use the Guilds civic normally but noticed something about it in respect to the infernal while playing as Hyborim. My wars had been going well with only a few hiccups and I'd established a substantial empire and in my core cities the populations were quite high with 60 in Dis and several others cities at 30+. I'd set myself up to adopt guilds since it gave unlimited specialists. I finished researching the tech and adopted the civic which then killed my economy. The city governors had apparently decided that since no one need to eat, they didn't need to be paid either. Virtually the entire populations of all my cities were assigned as engineers. The only exceptions were in a few new conquests where bards were the favoured ones to get the initial border expansion going.
If the AI uses the same rules as the governors then there could be problems here. In my particular case I went through every city and reassigned them manually (very tedious).
As I was playing the Infernals, my citizens didn't need to eat, but I still thought it was beneficial to work some of the city tiles. I went with mined hills both with and without resources since there's the small chance that a new resource will be discovered. I also worked all cottages since they will develop (as well as all towns and villages). With the remainder, I split them evenly between engineers, sages, merchants and occasionally bards in cities where I wanted more culture. I don't know what the optimal split would be, as I guess it's context dependent. If you're working on a particular wonder it might make sense to assign all engineers in that particular city, but not empire wide. I don't know if the issue would have self corrected once my gold reserve started to run out since I assigned the entire infernal population manually as soon as I saw what had happened.
I was using the previous version (2.1) for this game.
