Hello,
I will submit your suggestion for consideration, but please remember that suggestions are put forth as things to be considered by the devs, not guarantees of implementation. At present, we get a few fragments of paygated ninjas like Asura for 500-800 scrolls, so expecting a full recruit of a paygated ninja for the same amount is probably unrealistic, and, as a result, this may not be implemented.
Thanks and have a great day!