Rear Engine Heater Lines Loop Install

[lcm0027]

I temporarily want to run a loop on the heater cooling lines while we rerun the heater lines under the bus. We are keeping the 2 heaters in the front (under driver seat and defrost) so to help with cooling in hot climates. Do I just need to loop the hoses together before or after the pump that they run to? Please see picture for reference and my poorly drawn lines.

Also the valve in the picture doesn’t seem to close all the way. These valves I believe are already turned off but I think it’s open a bit and coolant is still able to flow in that circuit. Is that normal?

The main valve I see on top of the engine is turned all the way off.