@GaChicklette, here's a link to my post about the ducklings (with pics), if it's of interest: https://www.backyardchickens.com/t/1145327/runner-pekin-crosses-color.
LOL...I have a fawn and white Runner who's a hoot. She hatched Runner/Pekin cross ducklings - they're beautiful and awesome foragers. The Pekin drake is a nice, mellow guy who loves the water - I mean really loves it. I think he'd live in water if he could.
Another identifier would be if you've...
Sounds like the farm store mix-up strikes again.
I think you may be right...the one in the lower right-hand corner looks Runner to me (seems to have the right bill shape, anyway) and fawn and white makes sense. The other babies could certainly be Pekins, too. The TSCs where I live sell Pekins...