I have a city with 25 barracks. I take out literally everything I don't need. I have the barracks, 4 cottages(farm city). Feasting Hall, Academy, and relief station are the only other buildings there. All barracks are level 9(except for 1 lv 10 and a lv 4). When I need to send troops over, i send over my politics hero, demo my lv 4 barracks and build a rally spot.