Army units are due to their upkeep, which is the biggest cost factor of course part of the economy and their specific efficiency does play a considerable role. Still I want to focus that thread mostly one income side of things. The payoffs between occupation, sacking and razing may be of interest though. At the first sight the net gain by sacking & razing is quite high and seems to be linked to the development of the city. So far in my Suebi game I have only occupied, has the land has been Germanic apart from the Bohemian land of the Boii. I could use their buildings without any penalty - no Celtic temples - and wanted to get a couple of core provinces.

BTW, does anybody know if sacking or razing costs a building slot? Another thing to check later, I'm on a short holiday.