Move 4 Functions to the Maths & Trig Category
SUM is in the Maths & Trig category
AVERAGE, COUNT, MIN and MAX are in the Statistical category
My suggestion is to move these functions to the Maths & Trig category.
Here are some reasons why:
1 - The AGGREGATE and SUBTOTAL functions are in the Maths & Trig category
2 - There is a dedicated Maths & Trig drop-down on the FORMULAS tab so they can be found easily
A.C. Wilson commented
Or, simply combine the two categories into "MathS, Stats, & Trig" [UK]/"Math, Stats, & Trig" [US].
Kenneth Barber commented
It probably doesn't help that statistics is a branch of math, so it's hard to determine which category that these mildly statistical functions should be in.