Menzies don't seem to have a large number of staff anyway.
Not sure if BA will only pay for say 2?
It's like Aer Lingus in T1. Most of the time there's a single check in agent when the other 2 go to board a flight. Next to them, 2 or 3 Swissport staff on Finnair when loads range from 30-100 on an average day. Gets through those who queue quickly, and business / status pax have a short waiting time.

Some airlines pay for say 5 check in staff for an A321, 4 for an A320.
Occasionally there might be a shortfall as they're tied up on other products (or sickness) Other times, there could be 8 as they've nothing else to do for an hour or two so help out.

Saudia for example, have one dedicated business desk and the one next to it prioritises business (and will only pull say single travellers so that if a business passenger turns up, they're not waiting for a family of 10 with every baggage issue under the sun)

I last went to the BA desks back in April as I couldn't be bothered carrying my larger backpack around. Normally it's straight to security for me. Took a few minutes in the priority queue and they did pull at least one pair from the other queue first, but I was early and in no rush.

30 min wait for a bag the only time i checked one in from LHR-MAN (may have only done that once since on a flight from LAX or somewhere with 2-3 connections)

I had breakfast in the CP a week or so ago.
Whilst the Holiday Inn breakfast generally is better, i have to say that that the black pudding seemed spicier than usual and was rather good. The hash browns were nice and crispy unlike BA's soggy Rostis. Had a few of those