It may be that the Northern League has been forced into some such measures because the North-East was an early area to be deemed in need of special measures. They were not in force when I visited Thornaby and Birtley - each area was listed shortly after I left (not guilty M'Lud.) Numbers were limited, of course, and contact details taken. None of the matches I have attended so far has required masks, though I don mine for entering and leaving, when closer proximity is likely. I believe clubhouse access has been limited at some grounds near here of late.
When you mention numbers of spectators being cut down, is this a further limitation below the 30% of capacity previously set?
It may well be that the sort of measures mentioned will become more widespread - or worse - as the situation develops.