From my experience in Iron Banner and the videos I've watched there is a difference in the amount of time it takes to kill someone. In the lvl 4 video it took 4 seconds with an auto-rifle to get a 25-28 down to 25% health. Normally an auto-rifle in Crucible only takes about 2 seconds to kill someone. It is noticable but it's not a lot, I agree on that point. It should be tweaked some. For the skill ratings, if you're a good player, you'd be a good player at level 4 as you would be at level 30. In normal Crucible it's balanced so I don't see a problem sticking a level 4 with a level 30 on a team as long as their skill levels were equivalent. In this since account based would probably work. In Iron Banner that would be a different story since the gear/level will make a difference. It would be more complex as you would have to take into account how much defense they have how much attack they have what their truskill is. Then you need to balance all three.