Ku'ers mooching off of themselves is a good thing. If you're only getting three ku'ers in a window, you're doing something wrong. I typically was able to mooch a ku'er 3-4 times off of itself alone, which adds up to about ten potential Ruby Dragon bites per window, which is pretty good. They get away sometimes, but not *that* often. It took me about a month to get the Ruby Dragon back in the day, and because it was in actuality a month mostly spent doing other things while every once in a while dropping in to give the dragon a go, it wasn't really a big time sink. Stethacanthus was WAY worse simply because it has even more layers of RNG and there is much more actual time spent in trying to catch it than Ruby. And the big blues from ocean fishing were far, far, far, far more troublesome than either of these two.

Personally, I feel Ruby Dragon is fine. You pop in once in a while, fish for a few minutes, and then get back to doing other things for the day/week. If I were to ease up on the requirements for any big fish, it would be Stethacanthus's sculptorx2 requirements or the ocean fishing big blues' abysmal bite rates(combined with everything else involving them), which are all just pure life-sucking torture to get.