At various times I have been an Assistant Examiner (marker) for GCSE Maths and ICT. I wouldn't touch English Lit and a few other subjects for the very reason you give.Due to a move of region and school, I ended up studying "The Merchant of Venice" twice. I duly brought out some of the interpretations suggested by the teacher at the first school and they were dismissed as rubbish by the teacher at the second. That suggested to me that the whole things was highly subjective, one reason why I'm highly cynical about the compulsory study and examination of literature and (for slightly different reasons) of creative writing. I did come back to theatre in my 20s, but not to Shakespeare.
Returning to Latin, I wonder whether there is any traction in trying to enthuse students by having Latin translations of the lyrics of popular tracks which they have to identify (no titles, that's a give away)? No good asking me what constitutes a 'popular track', the music I am listening to was released in 1979!