Wow........
Seems awfully complex.
Are you getting/do you have PRM (parallel runway monitoring) positions or equipment?
What is the spacing between the strips?
Can't you descend in VMC regardless of what's on the other runway?
We join ours a vertical levels too. But we join with all 'domestics' independently in VMC; i.e. they get a traffic statement and thus are responsible for not going through the centreline due to traffic on the other side. It's fun watching two domestics pointing at each other; they have traffic of course on/before base.
Directors rarely talk to each other, it's look and go stuff.