Frankly, Tarunik's ISK efficiency is the most meaningless killboard stat of all (it's a ridiculous 98-odd% due to the LE supercap kills he's been on). I value much more the :goodfights: that someone can get (their war stories, in other words) than their raw stats. Sadly, stats-worship has led to people who simply won't give you :goodfights: any longer, and just blue-ball and/or uber-blob (anything more than say 3:1 to 5:1 numbers, given fairly evenly matched fleet comps) you.
I think the main answer to that would be to rework kill statistics (ISK efficiency in particular) so that blobbing wouldn't be so productive in that regard. Sadly, the last time this was tried (by Agony Unleashed, no less), they were forced to make their killboard private due to unceasing howls of "URDOINITWRONG".
As a side note: what would be a good place to discuss a revamped ISK efficiency calculation?
So, this is an awesome question!
Isk Kill/Isk Lost lacks a lot of nuance to it. Are the majority of your kills solo or do you only ever get kills in larger blobs?
Perhaps an initial starting point is to calculate your Isk Killed by multiplying each kill by the percent (%) damage you caused. This does not capture the whole picture, since EW inflicts no damage, but it is a starting point.
This would immediately lead to people considering the kinds of numbers they are bringing along. When you have 100 people on a KM, most pilots contribution is likely minimimal.
"Good job, 50 of us alphaed the Battleship! 100m isk for everyone's KB stats!" vs "What the ... I helped kill that Battleship and my KB stats only went up by 2m! I am not flying with you again."
It would be interesting to try and capture the impact of EW & Logistics, but lets start somewhere easy.