I have been using a finder-style guidescope for several years, right now it's an Orion SSAG with a Kwiq Guider on an otherwise stock 9x50 finder. I also picked up the Orion 50mm Guidescope to use with a QHY 5 II L, but haven't swapped it out yet.
Essentially, I figure as long as the guider is running at a better resolution in "/px than the main scope, you're golden, especially when you figure in subpixel guiding.
I get great results with the combo, guiding the mount to within 1" most nights, or 2" if it's real windy. Best guider ever.