I am not a number cruncher (they make backflips in my head) but is it thinkable that on a low level monster where all various stats are very low compared to yours, increasing attack power doesn't make much difference, but on a higher monster who's more on par to you, or higher even, it would matter.

It just seems to me like there is a damage curve where strength is sort of like the base curve, like people have been discussing lately.