instead of 1/5…1/4 would be more inline…1/3 would make cold dmg about near equal to the lightning build dmg but…i think 1/4 should be the way to go…because 1/3 wont make light stand up too much if the cold and light dmg are too near
lightning is supposeto be the highlight in end-game gear and semi-end game gear…so at 1/3 it wont be a strong motivation to swap to lightning…but 1/4 would be while not entirely killing cold dmg vs sundered enmies
edit:…2/7(29% effectiveness) would be between 1/4(25% effectiveness) and 1/3(33.33% effectiveness…thx for reply childe…motivated me a little to rethink for a more sweet spot XD