It's hard to say what will happen after having mixed Ashura's and Indra's chakra via spirit.
I mean , when they will wake up , will they have that powerfull mix (its a perfect complementarity) of chakra in them?
Or was it Hagoromo's way to explain that cooperation will lead them to something a lot more powerfull than if they fight?
I hope we are going to see Ashura's and Indra's full power modes via Naruto and Sasuke , before we see their cooperation.
That is going to happen if they fight 2 powerfull ennemies in 2 battlefields , or in a head's up match.