Even smarter, not one super capacitor but a whole series of them, which discharge into a low capacity rechargeable battery
Let's take a look at why that is not smarter. You are throwing away the energy density and quick charge properties, and increasing complexity by adding, most likely, another entire charge controller. As well, there is absolutely no need to use an array of supercapacitors, because supercapacitors are the solution to the problem of needing an array! They have fast charge and discharge, they already act wide and not just deep.
You're throwing away energy density by wasting space on having two power systems, and you're throwing away quick charge by including a power system without quick charge. You'll want a separate charge controller for the separate power system, and that means still more efficiency loss and still more cost. It just doesn't make sense.