I was at Pierz. I've been going at least once a year since Vern brought the sale there, and then before that when it was in Mora. Probably close to 15 years now :) There was some great stuff, some VERY unruly people (I think this year has been one of the worst for RUDE people, I nearly stood...
They just had a post on this not long ago. Summarizing, It seems that efowl steals photos from people for their "example" photos, and drop ship from other breeders/hatcheries, but on the upside, the quality of chicks seems to be an okay thing.
As long as you keep an eye on them, and no one is getting ran over too badly or starting to look listless, then you should be fine. I've mixed them before without a problem. How far apart in age are they? I always fall for those chicks in stock tanks too...lol.
Just wanted to add that there are no cameras allowed. I watched someones phone go buh-bye one year because they repeatedly were asked to stop taking photos and wouldn't listen. Also, please don't bounce checks...lol. They will hunt you down with a vengance. And remember "It's times the count...