another option to rank those with an identical average is to check the average points a ranker or rather the rankers are giving:
I.e. Person A and Person B are both getting a straight 5, but those who ranked Person A, gave an average of 12 points each Person they ranked while those ranking Person B gave only an average of 9. Wouldn't you say that the 5s of those ranking Person B are more valuable than those 5s of the rankers of Person A.
Of course this is also just a rough approach which can be fine-tuned a lot.
Just my 2ct