Extremely fancy, looks really cool.
This does not match the current building style of the Byzantine culture though. Red roofs, and grey and yellow walls should be and are the Byzantine colours, at least in Millénaire.
So if you plan to make a replacement pack as you did with the Normans anyway, just let it be and keep up your style. I would use it for sure (after recoding it to a separate culture of course)!
But if you changed the roofs to bricks and the brick walls to stone bricks, I see no issues in why not adding this as variant for the normal church.
