Due to playing My Colony, I've noticed that some of the categories in that game could be used here in Antiquitas as well:
Storage - Horreus' and Silo and other storage here
Roads - There are quite a few roads and it could use its own category, preferably not duplicated in Decorations.
Re Servants: I saw this suggested for vehicles/bugs in My Colony and wanted to also suggest this for the Servants here. Could we have a count of how many like we do buildings on the build menu?