HC in static recruiting means raid speed/time in this game.

So 8-10 hours a day for the first week is "hardcore" progression. There is usually an expectation to clear all the floors in that time span. Minimum ilevel savage raiding is actually more difficult than say a month or two or more in because you have to rely on crafted gear to clear the last fights

Plenty of people today likely can't clear E12S in full i510 gear. Like the fight is much different with 15% echo and i530 gear over full-crafted i510. So there are expectations of having a full understanding of one's job to do the most damage possible along with blind progression.