SWR have been managing to run about 56% of the normal service level, @ the average of 3.7 turns per shift which suggests ~270 need. 38% is 184 as you say which leaves 86 management staff to covering so a 2.2:1 ratio - does this match what mk1 eyeball sees?
I wouldn’t know, but I’d be very much surprised if there’s 2 guards working for every contingency guard. As I said, I’d be more interested to know how many guards should have booked on today, compared to how many actually did.