[wulfir]

The map will sometimes "remember" deleted units, so if you add units, then delete them and save the map, the unit ID tags (small flags) will be visable on map if you switch the ID tags on - and you will find them in the last hex the deleted unit occupied.

The best thing is to save the map before adding units, but say you have 14 ID tags scattered around the map - if you make a scenario and buy 14 or more units those ID tags will be "transferred" to the new units, if you buy 13 for example you'll have one ID tag left on map..., ummm..., you can also buy units and place them in one hex and then delete them - you'll have one ID tag on map then...