I'm asking the opinion of the JSA player here : I already own a JSA army pack, game wise : is it worth buying a second one ? The black friday price are quite tempting. I imagine Kuroshi rider can be converted in an arogoto, getting a second set of Ryuken looks great, I can use the oniwaban as a nice ninja proxy for my Yu Jin. I'm still left with some mini I'm not sure what to do with.
Sounds like you've got a plan for all but the Daiyokai. A horde of Keisotsu isn't bad to have on hand, all things considered, even if it's only for skewed lists.
If you have a plan for all the models, go for it! Ooooh, neat idea! Especially since I was looking at building a Mowang with dual pistols.
It works reasonably well if you cut it off at the wrist. A friend bought the Mowang, and did the dual pistol version as well. He had me clean off the arm so that he could hang the multi rifle on the back of the Mo'. I got the Red Fury as payment.
A ton of Keisotsu and a second Ryuken-9 SMG are both useful. And there's a lot of possible conversion fodder there too, of course.