[Fyron]

You have one line of components, but it has multiple tech requirements. Each tech level results in a new component, and each tech level only works on certain aspects of that component. So one tech level could increase cost and the damage done by it if it is a weapon, and the second could decrease the cost and decrease supply usage or some such. It is a grid because you essentially get a table of components that are all Versions of a singular component. So instead of APB I - APB XII, you would have APB Ia, APB Ib, APB Iab, APB IIa, APB IIb, APB IIab, and so on up to APB XIIab. The a's represent the progress from one tech area, and the b's represent progress form the other area. Thus, you get a table, or grid, of components rather than a single line.