There you go.
Minimal effort just export the data to the leaderboard.
Obviously the KDR is what matters the most in a 6vs6 but for the sake of those who care about the points i'd even export the W/L ratio to see which guild probably fails to kill but manages to do a good job at capturing/holding the flag. I wouldn't let it influence the ranking though.
To honor the top 3 dps / heal i'd export that too. Tank play can't be compared on a board as you can't tell who does the best job at guard and cc with numbers.
Of course only the kills/deaths happened in EC/CW matters for all 3 charts.
this would be perfect and (probably) not too hard to achieve.
personally I would not have flag-based 'wins' count, and only kills, so as to accurately ascertain the top dogs in 6v6 PvP at any given time.
I would also suggest removing the objective from Isha and the wc guards if such a thing were ever implemented, as well as implement wall in EC. these are the 6v6 scenarios, people overwhelmingly voted in support of wall, and if such a leaderboard were to be implemented then the scenarios used would need to be finetuned so as to remove any cheese dictating a 'win'. To the best of my knowledge, the devs have no plans with EC so it seems a very small thing to implement a wall if the people who utilise this map request it kindly
note: all of the above is said assuming devs find themselves with time to dabble in OP suggestion. naturally I understand and respect that other things take priority.