With infantry, I found groups of soldiers are named like
Alpha Black :1 - group leader
Alpha Black :2 - 2nd in command
Alpha Black :3 - 3rd in command
and so on..
Then the next group created would be
Bravo Black :1 - group leader
Bravo Black :2 - 2nd in command
and so on..
Once all the Groups Alpha - Zulu have been used then the next Colour will be used.
Alpha Green :1
Alpha Green :2
and so on..
Although, you'd need to find out what colours they were yourself. I don't have a clue.
Also if a unit isn't in a group, He's counted as his 'own group' so to speak.
For example, Alpha Black : 1 will be on his own then the next group to be created will have the group leader Bravo Black : 1. So in effect a lone unit is his own group leader.
Hope you find that helpful somehow.
As for armoured units I'm sure they'd work in a pretty much similar fashion.