I would change the allocations to:
Tier 1: The allocation
Tier 2: the higher number of points of either 25% of STHs or those with 2x the T1 allocation
Tier 3: 50% of STHs
Tier 4: All STHs
T1, T3 and T4 stay the same.
T2 probably stays the same for majority of games, only for those with small...
T2 could be the smaller of 200% of the number in T1 or 25% of STHs.
So for Luton T2 is open to the top ~2,500 or so compared to the top 5,000 or so, but Spuds would remain the same.
Good point.
Spud and Sheffield T1s are effectively the same (302 and 305) so makes sense T2 is the same, but not the same as Luton T2 which has a T1 of 381.