They’re so beautiful I love cayugas ! I have a few and I also have several other breeds with them and they all get along famously.
I have pekins , runners, Welsh Harlequins, Ancona ,khaki Campbells, Swedish, silver Appleyard, and more together with my cayugas.
The only benefit I would think of having just the one breed is if you plan on breeding them, but you would need a Cayuga Drake for that. My cayuga drakes are the nicest Drakes I ever had.
Still crazy because they are drakes

but they have been nicer than other duck breed drakes I’ve had in the past.
If you’re not breeding them then it’s up to you colors you want in your flock
if you get Pekins you’ll have black and white flock, which is pretty cool. There are other breeds that are white and have less problems than pekins (pekins have a shorter lifespan because they are bred for meat and get heavy quickly. They also tend to have leg problems because they are heavy.)
I have a few “white layer” ducks that have been wonderful and were still laying occasional eggs at 9 years old
Eta
Just took another look at your picture and I think you do have a Drake in there or perhaps two of them are drakes how old are they? Are you sure of their sexes yet
If I do see two Drakes and one hen you most certainly need more hens - 4 to 1 ratio is ok
I have a 9 to 1 ratio
You can tell by their voice only the females quack, loud and clearly. Males have a “cree cree” raspy sound