The 926 and 936 are very similar. Their placement demands will be similar. I definitely think 936's would overwhelm your room. The recommended listening distance Focal suggests are generally well advised, give or take a little. If one amp drive the 936's well, it'll be very similar with the 926's. I auditioned the 926 and 948 and bought the 936 sight unseen given the very similar sound of each.
I've got mine a good 2 feet from the wall. Any less and imaging suffers and bass gets boomy and muddled. They are speakers that want to be properly placed and toed. They will exploit the best amp you can buy too. I'm feeding mine power through a beefed up Pass F5 clone and they are simply amazing. Endlessly deep and wide, crisp, clear, and well focused. The depth ranges from faint and distant to attacking your face and wrapping around you. If you're not getting something like that from the 900 series they're either poorly placed or poorly matched to power.
I've got mine a good 2 feet from the wall. Any less and imaging suffers and bass gets boomy and muddled. They are speakers that want to be properly placed and toed. They will exploit the best amp you can buy too. I'm feeding mine power through a beefed up Pass F5 clone and they are simply amazing. Endlessly deep and wide, crisp, clear, and well focused. The depth ranges from faint and distant to attacking your face and wrapping around you. If you're not getting something like that from the 900 series they're either poorly placed or poorly matched to power.