Tiers? what tiers?
Club members can fly at club fields.
There is a small field for small area flight, like a 50%Yak hovering around or a eSlowFlyer,
and the larger field for large area flight,
like CombatPigs 90mph 10oz missiles or UberTelematsers or 91fs Mustangs.

All just members of the club with 2 fields, a slow field & a fast field by acreage