Is it possible to combine the Deco PX50 and Deco XE75 to create a faul-tolerant "multiple backhaul" mesh network?

In short, I'm thinking of a topology like so:

[ISP Modem + Router] ==> Ethernet Switch ===> Deco PX50 (main)         ==> 2x PX50 (secondary, PowerLine backhaul)
                                         ||                                     
                                         ||=> Deco XE75 (AP/secondary) ==> 2x XE75 (secondary, 6GHz backhaul)             

The intent is to have redundant coverage through a mid-sized home with redundant backhaul (i.e. link the main PX50 and a non-main XE75 via ethernet, and then everything else either uses Powerline backhaul or 6GHz backhaul).

Would this be a reasonable approach? i.e. should I reasonably expect the XE75 and PX50 units to "play nice" with each other and form a single wifi 6 mesh (and presumably this mix of ethernet/powerline/6GHz backhaul provides "the best of all possible worlds" in terms of performance and connection quality)?

I'd ideally like to have multiple "main" devices, but to my knowledge, this isn't possible. So, the above seems about as ideal as I can make this setup.

Thank you.