I have a question. I really don't know how things work in the UK school systems. But could this happen?
Ruby picked an obscure study so she could get into Oxford for her MA. She isn't even interested in the time period, but as it is not a popular one, it is easier to get into, so she tried for it and got in.
Once she gets there, maybe even takes some classes, could she changed her MA focus to one that she prefers and they would accept her, now that she has her foot in the door, or is that out of the question. In other words, we saw her change her major. Could she pull that one again at Oxford for her MA?
I am thinking no, because you were accepted for a very specific study and nothing else. But, like I said, if it is possible, I wouldn't put it past her.