That's what the leeway is for. Two hours per candidate seems like quite a lot of time and is nothing like any of the interviews I have been involved in on either side of the table.

I would agree that it's not typical. However I firmly believe that it is imperative for interviewers to treat the candidate as the more valuable commodity. As such, I will spend a fair amount of time per-candidate as I know they themselves are investing a good bit of their own time & energy.