I'm not a game designer. I'm a technical writer by trade, and the prevailing philosophy of that trade is to dumb it down for people. That's the short of it. A longer description might be that a technical writer's job is to take the guesswork out of using a tool. There's certain assumptions that you just have to roll with, such as the user being able to read, and have something they want to accomplish that requires them cracking open the manual. But a technical writer cannot rely on anyone making connections that are not explicitly indicated. So if the rules are going to mention that someone needs to charge a system before activating it, then those rules need to state what a system is, and what a charge is before they get to explaining what activating is.
However, it is not enough to explain this in the rule book. This also needs to be sign-posted on the cards so that players could figure it out without access to the rule book. So while I thought that using a hexagon on the back of the cards would indicate (or hint, even) that the backs of cards were somehow related to the hexagons on the front of the cards, that is not actually the case. The problem was that the hexagon on the back of the cards had no lightning bolts in it, and the hexagons on the front of the cards had 0-2 lightning bolts in them. There's no particular reason to suppose that the number of lightning bolts refers to the number of cards played face-down to charge a system for activation.
There's a reason to think that the empty hexagon on the front of the cards relates to an empty hexagon on the back of the cards, but no reason to think the one on the front means you don't need any cards played face-down. Where the front and back have matching empty hexagons it seems to convey exactly the opposite message. I believe I've seen the same look on many people's faces when they're told the logic of this choice, a look that says "This is in fact the opposite of what I would have guessed given the evidence in front of me."
My solution to this, following my design philosophy of implementing the most minimal change possible, is to put a lightning bolt in the hexagon on the back of the cards. Because if the column on the front of the card has an empty hexagon, the system requires no additional cards to be played face-down to charge it for activation. Similarly, if the column has a hexagon with a single lightning bolt, it requires one additional card played face-down to charge it for activation. Finally, a hexagon with two lightning bolts requires two additional cards played face-down.
So one lightning bolt per card back. Zero lightning bolts means zero additional cards face-down. One lightning bolt means one additional card. Two lightning bolts means two additional cards.