Yes it will give a "bad ammo" warning if there is ammo and no weapon. A unit like that would function perfectly OK in the game but I have rechecked every OOB in MBT and there were a few more like that and every Kornet team in various OOB's all came from the same source and it had AP ammo for Hand grenades which would make them useless but OTOH Kornet teams don't normally get into close contact with enemy infantry so it's not something anyone would probably notice. There were about 10 real bloopers but they were mainly confined to OOB's few players use but they have been corrected now. With over 39,000 units ten is pretty low odds
