See, not sure you need the component switch with the way you have your current setup unless you’re all out of inputs on the gscartsw and actually needed the extra inputs that the component switch provides. You have exactly 8 inputs to feed direct into the gscartsw. Would just need to pick up a few Component-to-Scart adapters.
The reason I suggest the matrix switch be last in the chain is because it can output any combination of inputs to any combination of outputs at once. You’re pretty much handicapping it and negating its purpose by feeding it into a regular one-console-at-a-time switch with no ability to mix and match (I don’t own the gscartsw so this is assuming it only allows one active system at a time and it sends that one system to both outputs).
On the other hand: if you had RGB systems on the gscartsw on input 1, Component systems on the Component switch on input 2 (here it makes sense to have the Comp switch), etc., followed by PVM on output 1 and OSSC/HDTV on output 2… your options expand. You could play SNES on the OSSC/HDTV, while a friend or family member plays Gamecube on the PVM.