Ninja tools in TI give out random stats while treasure tools has fixed stats. The tools you see in treasure are different from TI. Just because they look the same, it doesn't mean they are the same. Pay attention when you get ninja tools as it will give random stats.

Probably didn't really care to read to your post since since this is trivial. The gourd tool has been out for quite sometime ever since brothers ti was introduced. I'm sure by now someone who really cares about that stats would have pointed out that the scroll and the gourd both share the same stats. Also, don't jump to assume that it's a bug either just because you compared it with a different system that so happens to have the same tools.