The fix is here
https://forum.shrapnelgames.com/showthread.php?t=53000
Extract that ZIP to your MBT campaign folder for games patched to V17..
DO NOT apply this fix to a version less than V17 or you will be creating the problem this solves
For the MEU campaign, you will notice on deployment a USMC ID tag with no unit........ that little quirk goes back as far as I can check and it's left over from the creation of the campaign and
IS NOT a missing unit