We seriously needed a filler arc on this, preferably when Obtio was unmasked instead of the Kakashi filler. The other time I could see it placed was in the time between the Pain arc and the 5 kage arc, instead of those pt 1 flashbacks.
Why didn't they show us the two tailed beasts they captured before part 2 began?
No, but they portrayed it good, it's how i imagined Akatsuki being formed as well - most members would be unresponsive, and would only succumb after being defeated in a fight.
could this be considered canon? Correct me if im wrong but didnt kishi say something like he is happy he got to tell shisui story and how the akatsuki came into being through the game. As he always wanted to do it in the manga but didnt find the time or something like that.