I have no idea what the answer is for Exeter but it might be useful to consider parallels with other places. Manchester (before it became the Cathedral) was an infamous marriage factory. I understand that there were 2 reasons for this. Firstly, the church was a Collegiate Church with powers over surrounding churches. The Cathedral-to-be demanded a levy from its daughter churches for each marriage that they conducted so that anyone marrying in a daughter church had to pay almost a double fee - one to the daughter church and the other to go to the Collegiate Church. It was therefore cheaper to marry in the Cathedral-to-be. Secondly, anyone wishing to marry quietly could hide in plain sight by disappearing into the queues at the Cathedral-to-be. Whether either of those ideas apply here, I have no idea, but they may be worth pondering. Adrian B