Yeah. The majority of guild is there.

Be a fool to go off mining in advanced when the ores so much richer in the casual mines. 

Also there's various levels in a RP. 
Some might have less advanced worlds, more advanced plots, but some parts might be casual, while others advanced not quite fit in the other. Charceters, words, plots and writing may be at different levels. 

High casual is a good summery for one's that are not quite one or the other. 
Best of a few worlds.