Here's the cigar...I referred to the Greeks, not ancient Greeks. In particular, Ptolemy described Britain as in my above post. As you didn't comment on the Romans, I assume you accept that part.
Anyway, as to my original claim, that 'great' refers to physical size as opposed 'good, excellent, wonderful, terrific, awesome, fantastic, superb, exceptional, phenomenal, first-rate, sensational' or similar, still stands. đ