Yes absolutely you might have 5- 50 or more fights in a row with no rests ever.
How many ki points do we need for that?
How may spell slots for the mage?
No matter what your balance point is, other than instant recovery at encounter, you can extol some situation where the assumptions are out of whack.
So, what estimation of short rest to encounter ratio do you think *should* be used for the baseline balance between short and long rests?
That's not quite where I was going with this. It's not that assuming two short rests per long rest is necessarily bad. The bad part is failing to realize that the assumption doesn't always hold, and that you can't always predict when it will fail.
You said that you'll usually have about half of your points to spend in any given fight, and often you'll have all of your points when you need them for a big fight. You didn't mention that, sometimes, you won't have any points in a fight.
Budgeting short-rest resources is much more difficult than budgeting long-rest resources. A wizard is fine whether you have two short rests between encounters, or alternate 1/4/1, or even 1/1/1/1/1/1. A monk needs to guess how many encounters there will be between rests, and guessing incorrectly will leave them with wasted or excess ki points.
Of course, the monk will also be fine if they take a short rest after six encounters in a day, where a wizard is just out of luck, which might actually happen sometimes. Like I said, resting can be unpredictable. It's even
less predictable for short-rest classes, though.