Yes, you could kill a KW with 0-4 stacks of NV and be an idiot but that does not affect the % chance a key or organ drops it simply affects whether it is possible to drop or not (0-4 stacks of NV it is not possible to get either and at 5 stacks it is possible). The only thing that affects the % chance is MP level. Yes, if you want to be that nitpicky about it you are right, is that what you wanted to hear?