Best use of Dell WD19DCS

I have two Dell Computers, 7780 and 7520, two monitors U4919DW and U2723QE plus a WD19DCS docking station.

At the moment I have the 7780 driving both monitors (plus built in -but not used - cover closed) and the 7520 driving the U4919DW via USBC (plus built in -but not used - cover closed).

Hotkeys are used to switch between systems.

Having spent a lot of time studying the available documentation and searching for more information I am at a loss to know if it is possible to connect both computers so that each can drive both monitors.

If this is not possible would a replacement for the 7520 allow this or a change of monitor or both? e.g. the later 49 inch monitor and which dell computer that has two hard drives and good video capability?