Sorry, but I don't feel I can ask this question at the college where my student has an offer!
I remember from my undergrad days that it was fairly straightforward to change courses at Cambridge. A student at my college switched from Econ to Law, for instance. You'd hear of quite a few others in different colleges... I always assumed that you couldn't switch from say MML to NatSci, but recently heard of just such a switch - the daughter of a friend.
I accept my experience is limited, but I have never heard of a request to switch being denied, though I know requests won't be granted if you perform badly in your first year.
One of my charges has an offer for course A, but wants to feel quite sure she can switch to course B at the end of the first year if she isn't loving A. Both courses are within the humanities family and have similar entrance requirements. She has now heard on the grapevine that some colleges are more open to switching than others... she thinks her college might be one of the unreceptive ones.
Yet from my memory it was never really college-specific, it was more a question of making your case and getting approval from your current DoS and your prospective DoS.
So has anyone heard similar, that some Cambridge colleges are less open to switching? It would be useful for my charge to know, as she has a slew of amazing offers in the UK but is most tempted by Cambridge, on the proviso that she can make that change after her Part Is if she wishes.
It may be worth mentioning that her other offers are perfect-fit courses at LSE, UCL, Sciences Po and Edinburgh.