Fir + Kishu - same pot / Bad idea???

[Japonicus]

Sold as a Noble fir, I had several cuttings rooting around the base in same nursery pot.
Divided it all up today, and this cutting is pretty root locked with the fir...I don't have any shimpaku cascades
but if I don't sever these this year, it's going to be more of a problem the longer I wait.

Idea here was to develop the two into the same pot with the Kishu as a cascade.

 

[Gabler]

That could look good planted on top of the right rock.

 

[BrightsideB]

They are friends