Math means a brand split FUCKS with your choices.
You do not get the same number of possible choices after a brand split.
A = number of wrestlers or teams on the roster
Possible amount of combinations = (A x (A-1))/2
Even if you split the roster evenly so that B=A/2 then the number of combinations becomes a lot lower because Bx(B-1) TIMES 2 is always smaller than A x (A-1). An uneven split makes things worse.
Example 8 tag teams in the whole of WWE = total combinations (8x7)/2= 28
Brand split exactly in half = (4x3)/2=6 in each brand, two brands means x 2=12 combinations
Which is why the womens divisions are so fucked because they start with low numbers.
PS its pretty simple, same reason that two 25x25 ft apartments are much smaller than one 50x50ft apartment.