Gamelogics count as units too, so you need to consider them as well.
The same thing just happened to me but I have nowhere near 144 groups! There are still quite a lot of soldiers and it's in Zaragabad, therefore mostly CQC, so I've put lots of units into buildings; does that anything to do with it? I definitely don't have 144 groups...
A group consists of one or more members. Each individual unit counts as a group. Try to reduce the number of groups by looking at locations and start grouping soldiers that are close to each other and/or look towards the same direction, as these would conceivably be in communication with each other in reality. Set their Special: setting to None, making sure they are set to this disableAI "Move"; in their init line then press F2 and start linking them together. This will reduce the number of groups as the previous individuals are now linked in one group.