These are all excellent points, I would counter with this: most of the things you’re describing have more to do with the tactics involved rather than the design itself. Let’s say a stirrup was used in both (the technique of reloading it standing up vs sitting down) but one side’s bows were composite, had better bolts, a cranequin, would it really be be that dissimilar to an AKM vs XM7?
These are all excellent points, I would counter with this: most of the things you’re describing have more to do with the tactics involved rather than the design itself. Let’s say a stirrup was used in both (the technique of reloading it standing up vs sitting down) but one side’s bows were composite, had better bolts, a cranequin, would it really be be that dissimilar to an AKM vs XM7?