Here is an excel doc with prescribed poets going back as far as 2007. The highlighted ones in each year have come up on the exam. It is really difficult to see a pattern. Best to just pick five and study as best you can for 100% assurance.
its pretty much guarteened that a female poet will come up. there definely would be controvesional and sec would avoid this . but best bet is do five. especially when their is still alot of time to go to lc paper 2 2020