Hi there!

Yes as what others already stated they do stack.

There are already some posts regarding this made by some of the greatest players in the game. You may want to refer to these links to know more:

https://forum-narutoen.oasgames.com/page/show-post-31625-1.html

https://forum-narutoen.oasgames.com/page/show-post-30175-1.html

When in doubt, we c*ways try to figure things out on our own. Afterall, kakashi NPC is always around the corner!

Or if you have friends, much better as you will have more control over the opponents' skills.

Ex: debuffs from shikamaru (chunin) againts your immune ninjas (Kushina Red or Choji GNW) [cancel buffs/shield], and so on

Hope this helps!