IIRC motors have a much higher peak than that (e.g. when starting to turn from a standstill), and they are not really comparable to light bulbs or other simple resistors.

C-Ratings on batteries are not realistic. So much so, that calculating it the way you did doesn't really lead to useful results any more. But higher C-Rating usually means lower IR, and that should lead to a battery that stays cooler and is less stressed by the load you put on it and deliver more punch or voltage under load.