Breaks my heart too! Re-homing birds is not easy on the emotions!
I don't care what anyone says -- but in my 9 years of backyard chickens I've found that alike breeds do bond better with each other -- I have two Dominique hens that were babies together and as 3-yr-old adults they're always toodling around close to each other. It was the same when I had two Silkies together -- they toodled around together away from the other hens. A single breed without a matching breed as a companion in the backyard flock is practically an outcast. Some standard size breeds like Leghorns, Barred Rocks, Breda, or Rhode Islands don't seem to mind being loners but toss in an alike breed like themselves and it changes the dynamic -- they pal together. I've watched videos of different breeds and when they settled down for mid-day snoozing it was interesting how most of the alike breeds huddled in their own little group.
Your birdies are so adorable!