Simpler? What use of the word simpler is this? How do you plan to attach the radios? Buy boards with radios? Simpler but way more expensive.
Do you solder? I'm not much good at it and that limits what I can do but once in a while I solder anyway. I like to use DuPont Cables with female ends that slide snug onto header pins and sometimes make T's or put a chip in the middle, solder joins and heat shrink tubing to insulate are the way to go.
An alternative is to use telecom splices. A box of 50 runs about 25 cents each IIRC. Just be sure to get the right size range for your wires. With hair thin wires, splices are completely worth the money, most people can't solder those at all.
SPI is a bus. The 4 wires on the master go to every device on the bus and 1 wire goes from the master to each device you would have not listen or talk to the bus. They're not turned off, can run set tasks, just no bus comms.
Radios will be many times slower rate and radio messages can step on each other but that's what packet retries are for, right?