Count all the parts first, that way you’ll know if you actually fucked something up or if they just included a pack that has 12 screws in size whatever instead of 10.

If you counted them first to begin with and still have leftover parts… good luck.

Is that an amogus on the left side of the scroll?

Some things, like wooden dowels, can be overpacked in my experience. But most metal things aren't. My guess is that their machines are calibrated on weight, and they are on the cautious side with the lighter things.