The power plant can only supply so many electrons at any given moment. You get the task of distributing those electrons and prioritizing where they go (which capacitor). That determines their charge rates relative to one another. Getting away from the over-thinking electrical description...
The analogy of filling a water storage vessel is quite a good start. Now imagine that you have a few water vessels to fill (3 in this case) with that one fill-pump. You must determine which vessel you'd like to fill at the highest rate (and 2nd and 3rd) based upon the needs of the thirsty folk draining each of the vessels.
In this scheme the distributor is the "sharing" valve that diverts the water flow at the chosen rate to the 3 vessels (any one of which could be receiving zero flow* at times).
All of the vessels have drain ports that can (alas) outpace their fill rates unless (in some cases) the sharing valve happens to be diverting the highest rate into that particular vessel.
You can apply this analogy to energy storage/consumption and to cooling capacity/use.
Back to the over-thinking: this is a relatively common scheme and is rather efficient, allowing numerous components of the system to operate at a constant, optimal pace (or a comfortable range) while making fewer components of the system strain in order to adjust/adapt.
* This is indeed a simplistic analogy. For example, in-game if I'm messing around in the RES or the CZ, I can have zero PIPs to engines and fly around (no boost) without worrying about not being able to move, or worrying about my engines overheating. Ok, so we have a leaky sharing valve - that explains everything, right?
except where the water goes when all the vessels are full - darn! Oh and this detail, and that one, and - Ahh!
Less tech, more gaming...