display "pupil of the month" from given range data

ok, I have spent quite a lot of time creating a multi-sheet workbook to allow teachers to enter student names from a dropdown box, then autofills in some stuff etc etc. (this is done from the "cards entry page". (the "calculations page" does all the work, the other sheets are for display purposes.) If you look at each tab after the "cards entry page" you will see what the "calculations page" does.

Now the teachers want to incorporate the "Pupil of the Month" into it.

I have added the POM sheet (& POM house points sheet) in at the end of my original.

What i need is the POM sheet to show which pupil/s (name) by class/subject, accumulated the most Lilac cards over each month. note the POM sheet i added is only for one month. is there an easier way to display this information for each month, other than 12 sheets ?. This part is way over my head now...

would greatly appreciate any help on the formula required to calculate the top pupil/s per month.
sometimes there are more than one pupil in each class that attains top equal counts, so the POM sheet needs to be able to show any joint-equals.

spreadsheet is attached