Quote Originally Posted by womble
"...drag the 13 strength unit tab button onto the 14 unit tab button..."

Or you can just hit M to automerge. This will rationalise your post-Marian units too, which may or may not be what you want (retraining refreshes a unit's numbers without the experience averaging that combining cards does).

This helps too. Thank You!

Strength and Honor.

Celt Centurion