It's improved over the 2+ years for a new clearance with a real background check. If he hasn't ever had a background check there are two usual delays, as noted some issue of some kind, but the major trouble is usually workload, not only are they doing a lot more now and that is bogging down the central facilities, if it goes to one of the local or regional sites for actually accomplishing the check and that site is overloaded that drags it out even more.
In the OLD days a NAC or ENT/NAC was good for an interim Secret. National Agency Checks were just that they checked with FBI, SS, USFS, NPS (yep, I guess to see if you pissed off Smokey Bear), etc. Abackground check is an agent actually going out and interviewing people in person or by phone. A BI used to be good for a TS, any additional things, SCI, SBI, SCCI, etc require additional processing.
Remember he is working with a federal bureaucracy that keeps getting "improved".