Last year my TSC had "assorted reds, straight run" and "pullets" and they couldn't tell me a breed just that they were pullets.
The pullets turned out to be white Leghorns, and yes all of mine turned into pullets.
The reds, I got 2 RIR roosters and 1 Red sexlink pullet.
Last year I reached in and pulled out of the straight run standard bucket a bunch of Silver Pheonix, some White Cochin, and one Mottled Java. I have one that looking back I think might have been a splash something, it had that silvery grey down with a yellowish background to it. It didn't make it.
They also had a lot of ducklings I ended up with a Mallard, 2 Cayugas, 1 Brown Indian Runner, 1 White Pekin, 1 Who knows what black with white splotches, but not an Ancona...
Last year I got some chicks from a TSC bin labeled Leghorns. Two are Sussex (which is cool) one is a Sussex Rooster.
The others where these brown hens with white feathers dotted here and there. They lay a rosey darkish brown egg. I do not know what they are but they are not Leghorns.
my tsc was fairly limited... they had a bin of ducks, a bin of cornishX, a bin of "assorted reds", a bin of assorted "red pullets", and a bin of "assorted bantams"
of course, customers and untrained TSC employees were picking up chicks and putting them down in different bins... by the 2nd day after their arrival, there were about 3 bins of half red and half white chicks, with the occasional bantam running around. the bantam bin was mostly full of just bantams.
i would suggest finding out when they are getting their chicks in and get there quickly, before everyone has time to switch the chicks around!
Our Tractor Supply (Elkton, MD) is really limited on chicks. They had a bin of straight run RIRs, a bin of RIR pullets, and a bin of straight run ducks (mostly Pekin, but some Rouen in there, too).
I really wish they had a better selection (my luck in shipped chicks hasn't been great the last couple of seasons, and I feel horrible for the little ones that don't make it), but most of the farmers around here are interested in basic hardy brown egg layers, and some Pekins for meat, and that's about it.