> Are you saying there are some unstated engineering limitations that would hinder getting to the desired "C" by connecting more battery cells in parallel?
When connected in parallel, each cell has to discharge at same rate within a small margin. That means you have to match cells by capacity and internal resistance during manufacturing process. The more cells you put in parallel, the more chance some of them will age differently and cause whole battery to underperform or fail spectacularly.
Because the load is spread equally if there is a difference in the capacity / internal resistance of the battery it can cause a higher load on it than it can safely discharge at that moment.
Without this we wouldn’t ba able to make battery packs with 100s not to mention 1000s of cells and even smaller battery packs would die much much sooner.
A good analogy would be if you have a boat with multiple people rowing and one of them can’t hold the same pace if you don’t adjust for it you aren’t going to hold course and if you don’t let the man catch a break they’ll pass completely eventually.
> And why the batteries have to discharge at the same rate in the first place?
It's the definition of the cells being in parallel. Since they all have the same voltage difference (as the fronts and backs are all tied together with wire), they have to discharge at the same rate. The balancing dogma1138 was describing is done to allow some batteries to run at slightly different voltages so they all are at around the same state of charge.
When connected in parallel, each cell has to discharge at same rate within a small margin. That means you have to match cells by capacity and internal resistance during manufacturing process. The more cells you put in parallel, the more chance some of them will age differently and cause whole battery to underperform or fail spectacularly.