So how many separate "circuits" do you want? And you want each circuit to be controlled by a motion sensor - or by a day/night sensor - or by a manual switch? Or do you want one switch and day/night sensor to control all the circuits?

i'd love to see the wiring diagram for all of this!

What your electrician is describing is the simplest way to wire it, not the most flexible. With traditional 120V lighting, motion sensors usually switch power directly, which is why they’re often built into or mounted right on the fixture. As soon as you want the sensor in a different location, plus day/night behavior and a wall switch... the wiring quickly becomes complicated and hard to change later. If what you want is motion, daylight sensing, and manual control all working together, it helps to step back and decide whether you’re designing electrical circuits or designing how the lights should behave.

There are really two practical paths: remote 120V motion sensors do exist and can control other lights. That’s a valid approach, but every added behavior usually means more wiring, possibly more relays, more electrical boxes, and more work if you want to change anything down the road. Or other option is a low-voltage automation approach. With low-voltage sensors (often 24V) and centralized logic, a single sensor can control multiple lights, combine motion with daylight, and still allow manual wall control without rewiring later. Changes happen in software, not in the walls.

It’s not that what you’re trying to do is impossible. Lighting just works better when you design how it should behave, instead of hard-wiring every decision. Once behavior is handled by logic, adjustments are easy. When everything is hard-wired, every change turns into a construction project.

The TREEWELL Motion Sensor should be wired to a wall switch. By following these instructions, you can manually turn on the lights, bypassing the sensor (i.e., auto mode):

"To activate, turn the wall switch OFF and then ON within 2 seconds. The light will remain on for 8 hours, then automatically turn off at dawn. To return to Auto Mode, turn the wall switch OFF for more than 2 seconds and then ON."

That’s a simple 120V solution using timed switch control actions.

That "simple... solution" is commonly found on many if not most motion sensor lights...

“Simple” doesn’t mean technology stops evolving. There are newer ways to approach this today, but that’s beyond the scope of the original question.