Hydraulics for Backhoe

Here is my situation. My tractor hydraulic pump is pumping 26 GPM to the loader valve open center without power beyond. The backhoe valves require 9 to 14 GPM to operate.

The original plan was to run the loader and backhoe valves in series loader first backhoe second. I think this will reduce the whole system to a 14 GPM flow losing 12 GPM.

The next option was to add a divider valve after the loader valve in the series and divide the proper amount to the backhoe and any excess will run to the reservoir hopefully then running a 20 something GPM system still. I talked with someone at Surplus Center (this is the part that I do not understand) and they told me that I could not do that because the backhoe valve will be adding a pressure to the outlet side of the loader valve that was never there before and COULD crack the loader valve or the loader cylinders MIGHT move without me moving the lever.

Is this true? I would really like to run the system without a selector valve that I have to throw everytime I want to switch between the two.

My loader valve does not have power beyond capability at all.