Lightning mate, you make an excellent point. I'm intending to get everything done in a total of four sittings.
At a pinch I could probably pass Radio Nav in Jan, but I don't want to risk lowering my marks in the other subjects - or worst of all failing one.
I'm keen to ensure I get first time passes in the 90s so may as well make use of the number of sittings available, while still leaving two 'spare'.