Hell yeah. And the next time you call that group, he will call them Archers. The descriptions are not only wrong, they're not consistent.
And what if the player wants to group his army in a different way? (Maybe he always leads with Cavalry, and so wants them Group 1.) Better to allow players apply labels themselves! ... - But at least try to get the names to follow the given structure, if player-assigned labeling is too hard.
How to reproduce this bug? Just play the game!!