Here's another take on this scene. Done quite a few internally lit scenes with this model lately, but this one I think is worthy of showing.
It's meant to be "Sponza atrium by moonlight". The sun is very dim (0.75), with 10 other internal lights. I'd really like TG to have directional lighting, but this is the best I can do. There are 4 on the ground floor, 2 at the far end 1st floor and 4 each on the 1st floor side corridors.
Again the GI settings are high as per dandelO's method (thanks).
C&C welcome.