Hi there! Year 12 here and I'm assuming this is a GCSE essay, I had a similar style question at GCSE. Your structure for the 16-marker is pretty much spot on, the only thing is I was told to ALWAYS start with the factor in the question. My structure was always: introduction, factor in question, another factor, another factor, conclusion (you seem to have a very small paragraph just before the end, you can just add this on to your 3rd paragraph!). Also you should avoid using first person to get into the top bands.
I haven't actually studied Anne of Cleves and I've only recently studied Thomas Cromwell but I think I can give you some general feedback. Your introduction doesn't really seem to flow to me and I think you should have written more about the factor in the question in your intro, I think you should have written something along the lines of "Undeniably, Cromwell was one of King Henry VIII's most key and trusted advisors
(you don't actually need this first sentence!). While the failure of the marriage to Anne of Cleves was a reason for Thomas Cromwell's execution, it certainly was not the main one. There were many reasons for the execution of Cromwell such as ... and ... Undisputedly, however, the main reason for Cromwell's execution was ......."
In your intro you need to sound assured (without a doubt, undeniably, undisputedly etc...) as it will help to make your argument stronger. You need to identify (within your intro) another factor that contributed to the execution of Cromwell and the main factor (thus, you should have 3 factors total, including the one in the question).
Watch out with your capitalisation (Henry, the King, the Crown, Duke of Norfolk etc... they all should always be capitalised).
I think the big thing about this answer is that it reads like a story and no essay answer should read like a story - you need to explain WHY, rather than tell a detailed story - Yes Cromwell said the Duke had come into contact with someone who was suffering from sweating sickness...so what? How did this lead to his execution?
Your own knowledge is pretty good, it's just a little too vague (think of putting like in 1532 this happened etc and being a bit more specific) and I think if you try to stop you answer sounding like a story it could get better!
Sorry for the somewhat extended criticism - these criticism relate to somebody aiming for the top band and going for full marks (and you could be, who am I to know!) but if you incorporate some into your answers you could improve your answer a lot and potentially go for full marks. In terms of marks I'm not sure what I would give this, as honestly I've somewhat forgotten the GCSE mark scheme criteria for grading but I don't think you'd be getting into the top two bands (band 4 and 5 i think it is?) just yet, maybe a band 2 or 3?
If you have any questions about anything I've said, please just ask me and I'll do my best to help!