With the fragment refinement system we now know Oasis games has a bit of leeway with what systems they can add to the game.
So please for the love of god add x2 speed to Arena, Matsuri, Sage War and ESPECIALLY Great Ninja war.
X1 makes the game more time comsuing in a bad way as combat is just way less exicting and fun to watch on x1 speed.
And if you feel like its fine, watch a 3 Sasori 100 Puppets with all their puppets out attack and tell me nothing is wrong with that lol.