I wonder where neil2 got the "english to latin" bit from then but we'll probably never know. It just seems odd that an anagram of To Latin is In Total which is another possible 2,5 answer (dependent of course on other letters)
Thanks Zhukov.
I'm still puzzled though. I have been assured by others that the clue was printed simply as "comprehensively", rather than "English to Latin: comprehensively", but the latter version seems plausible given that IN TOTAL is an anagram of To Latin.
I can only assume there were two sets of clues or different versions in different parts of the country
Ah well, looking at neil2's two posts- each with a different version of the clue- there seems to be an even split between IN TOTAL and IN DEPTH and everyone seems to think their answer is correct, so as everyone seems happy I'll leave it even though I don't understand what's going on