I think what he means (and this goes for Pinnacle too) is that there are a lot of flights that XJ, CZ, and 9E do for NWA that are not even close to regional flights. Compass has the most of them I believe. Here are some examples:

Compass: MEM-PHX, DTW-Monterry Mexico, MSP-BOS
XJ: DTW-DFW, DTW-ORD, MSP-MSY
9E: MEM-BOS, IND-SAT, MSP-SAV

Its just a sign of the times now, I am sure this goes on at every airline. Its all about how many people are going where, but in the case of DTW-ORD you could put 10 757's on that route and it would always be full