At Skywest the most junior base on the EMB is FAT and on the CRJ is MSP but people seem to be getting a variety of stuff out of training. The most recent EMB class had a few people get PDX which is pretty senior, and an entire recent new hire class on the CRJ got SLC.

Just looking at the numbers here are the most junior bases:

EMB: FAT, PSP, SLC

CRJ: MSP, ORD, IAH, COS