But you could just... tune the systems to break down at the appropriate number of dice instead.
Actually, you can't. Ultimately this is a symptom of the fact that Exalted uses the exact same resolution mechanism with exactly the same parameters for every single task, whether it is "hit person with sword once" or "apply medical treatment to 100 refuges". By default, someone with maximum skill is rolling 11 dice, or 21 with a full Solar excellency.
Without dice tricks you have
exactly one parameter you can vary to get the system to spit out the right probabilities: the difficulty.
The problem is, you only have one variable, but you have 10+ simultaneous equations, and it is not possible to solve a system of more equations than variables! You are gonna have a lot of probabilities miscalibrated.
This becomes particularly obvious with opposed systems, most notably combat. There need to be limits on the actual range of effective offensive dice and defenses. We want characters with at least a reasonable combat investment to be able to hit and able to defend a reasonable fraction of the time, even against powerful opponents. We want this for two reasons: first, since combat is an aggregate of many rolls, it will magnify a small advantage on individual rolls to still give high odds of final victory to the person with that advantage. Second, because "eh, there is no point attacking because you have basically no chance of hitting" is super not fun.
By contrast, if a contest between two characters usually involves just one roll then it needs to give a large per-roll advantage to the character with more investment. For example, with Stealth vs. Awareness if one character has invested in Stealth charms and the other has not invested in Awareness charms, the Stealth character should have a
really good chance to beat the other guy's roll so he can sneak past.
The way you solve the problem (one variable, many equations) is to add more variables. The idiomatic way of doing that in Exalted is to add charms; competence in an area of skill is not just your ability dots but also how many charms you have bought. Some of those charms will be math-boosters, and those ones
can't be standardized between abilities, because as above different abilities need to scale differently with degree of investment.
They could have achieved the same thing without dice tricks and just standard dice-adders, with the amount of dice-adding you can buy in an ability varying between abilities. I suspect they thought this would seem really weird and inelegant. "Why is the Melee dice cap 4 but the Medicine dice cap 10?" ¯\_(ツ)_/¯
As I said, I don't
like dice tricks, I would in fact be fine playing an RPG that used a spreadsheet RNG with no dice and algebraic formulas for probabilities that were displayed to four decimal places. But I'm a weirdo and normal people seem to enjoy rerolling stuff.
If for some reason this is actually desired or needed (why are you balancing Ability A around a dicepool of X and Ability B around a dicepool of effective X+Y?), an easy way to do this would be to cut the idea of excellencies / generic dice-adders and give each ability its own custom dice-adding charm with its own cap, like how Exalted 1E gave Melee Excellent Strike, but Brawl didn't have a dice-adder.
This would serve the purpose you want, and waste vastly less time.
That's what I said, dude. Literally right there in the comment that you quoted.