I pretty much structured mine as I would a standard essay, so somewhere between a Legal Studies Response and an English response. I don't think it matters too much though, but yeah basically - Thesis, Intro, Body paragraph for each point/argument, Conclusion.
I would say that it was a combination of both, I would say more logical than sophisticated, but you draw out the facts and flesh it out with your own opinions and arguments. Basically, just have an opinion, and show how you came to that opinion/why you think it is correct by each argument/idea you have.
Overall, just don't panic, be creative and be original. It doesn't really matter how much you write, but just get through it all, have a strong opinion and show the markers why that is. The exam was 2 hours right? I think I spent 10-15 minutes just reading and going through sources and what not for each essay, and then I ended up only writing maybe 5 pages for each? But yeah, I would say at this stage, just prepare for things you could say, for example an argument for bias/omission, changing values over contexts etc. Just depending on what questions they give you.
Good luck, if you need any further help I'd be happy to answer!