Searching my files for photos, but we have four MTH yard lights in our through yard. They look nice, but realistically, they're more for decoration than light output. If you can get LED bulbs to replace the incandescent ones, they'd probably throw a lot more light. One of these days we'll get around to changing to LEDs.
Matt Jackson "The best service you can provide for the hobby is to pass on what you have learned."
Here is a pic of my yard with the Lionel 6-12759 tower lights and you will notice all my switches have a double headed Lionel 6-12927 #65 Yard light. It works pretty well. My table with overhead lights out looks like a night time scene, not bright, but workable.
Michael's Crafts has LED yard lights in the Christmas stuff. 8 9/16" expandable to 12 3/8". The rack and each light is individually adjustable. Price about $22. 30% off today! (3) double A batteries or 4.5 power supply they sell also discounted.
If at first you DO succeed,try hard to hide your astonishment.
When I was a brakeman for the Quanah, Acme & Pacific, our yard at Quanah had NO lights (except for our lanterns). It may have gone back to the WWII days when blackout mentality was everywhere. I don't remember any lights in the SLSF Oklahoma City yard either. It was just DARK.
I think it is great that your O gauge switchmen will be able to see on the midnight job, but no lighting in the yard is very prototypical.