Base/Main/Game also lacks virtual table... one can say it manages memory and it can even be called BaseMgr, MainMgr, GameMgr... but it is not a manager in the sense of nwc code ~ the class is not derived from BASEMGR (0x44D200) whereas the others are (and some other). There are also has subsequent initializations to temporary memory when you are in campaign dialogs or choosing a new map, all things that make it different from the others. In the big picture the impact is ~~0 when suitable name is used.

Random map creation also uses a central structure, which is simply named "random_map_generator" according to mapeditor

Game Data/Details/Info/... is the most representative name I can think of; base and main are good candidates as well albeit less informative.