Subteams are created by comatMode RED, enableAttack or joining two groups (as a bug).

https://community.bistudio.com/wiki/doFollow has the suggested affect/functionality - but with these implications/downsides:

1. It also makes them return to formation as well
2. It forces them to exit vehicles. Ref: https://forums.bohemia.net/forums/topic/219774-strange-perplexing-problem-with-dofollow
3. It is not always working reliably (when two groups are joined)

Command syntax could be the same as with doFollow.