I guess I just assumed a rangefinder, if a view camera wonder how birght a MF lens will be? I have both Speed and Bushman 2 2/4 by 3 1/4 with 90mm and 100mm lens, when using the ground glass image is rather dim.
I primarily use an Arca Swiss F-Classic 6x9 monorail for shooting 6x9 and digital. The ground glass is reasonably bright with an ƒf5.6 partly because the Arca Swiss ground glasses inforporate a fresnel. With the Nikkor-M 105mm ƒ3.5 it is quite bright, and with the ƒ2.8 Xenotar as well. I even us a 150mm Apo-Ronar ƒ9 as my slightly long lens and its bright enough, but does need the dark cloth.
Linhof went to great lengths to make sure that there lenses and cams worked well together. That said I had a friend that had a 2x3 linhof with a few lenses that did not have matching serial numbers and they worked good. One of them was a 180mm tele xenar and it tracked just fine. He later sold the tele xenar to me and I have used on my horseman 985 with a Horseman 180mm cam and it seems to track just fine. Your mileage may vary as they say.
My Crow Graphic came with a Wallensake 135, like Linhof the following focusing arm is matched to the lens, but I traded the Wollensak for Zeiss 135 and it focus just fine. It may be just the luck of the draw.
I think it is due to the fact of its actual focal length, not the engraved focal length. Brand x 150mm might be 151mm and brand y is 149mm. Those 2 may not work. Did I say that right?