3 coordinators (zigbee/thread) - detached house - repeater or not

I’m starting out with Home Assistant and have some questions about setting up my home network.

I have:

  • A detached house with solid construction and concrete ceilings, a basement, ground floor, upper floor, and a garage 10 meters away.
  • Three coordinators (2x SMLIGHT SLZB-MR4U and 1x Sonoff Max, each with 2 antennas)
  1. Can the SMLIGHT MR4U and Sonoff Max units even work as repeaters for the master MR4U?
  2. I’ve read that coordinators used as repeaters can only be connected via Wi-Fi – not via LAN.
    Is that correct?
  3. If so, then it’s probably better to set up three “wireless links,” each with a coordinator.

I need a device in the basement to get good Wi-Fi coverage.
Router and “master coordinator” are on the ground floor.
Another coordinator can be added on the upper floor if needed.

Does anyone have any tips for me?

  1. Should I use a repeater or not?
  2. Any other tips based on experience?

Many thanks!