Not sure about kisame, but kimimaro, guy and hidan are now guaranteed during first 13 seal scrolls in seal treasure (at least thats exactly what i got at the same number of pull on 3 accs)

Those 20 pulls have fixed ninjas in their drop table after certain number of pulls. Honestly, its not a bad idea, since getting 3 3* ninjas right away at lv10 makes early life a lot easier th*ing crap team7. Also 20seals isnt much of an investment.

edit:

found a link where that was already mentioned: https://forum-narutoen.oasgames.com/page/show-post-26615-1.html

Those rares arent fixed, but they appear exactly on set number of pull.