I've no idea what levels they have on different points totals, but like the Blades, and partially down to the EFL rules, they could book one ticket per individual customer number and prioritised by different points levels, then all ST holders, then Members, then non member etc. So anyone bought in the transaction had to match the points and/or status.
Very similar to what we do (depending on where the points level was set).
The 6 per transaction rule, is an EFL rule, as is the selling order and various other little bits.
Pretty sure Wembley also now have designated areas as family, singing, standing etc, but that's in their guidance, not the clubs.