Well, Pikaboo solos 2v2 gladiator teams as well. But I think the chance of a successful boost is immensely higher if you have 20-30 ilvl more than your opponent. Especially in the lower brackets as a DPS. A lot more than I think you realize.
One 6 KS can probably kill any healer at 1000 rating if you have 230 ilvl and they have 195 ilvl. But if you scale the ilvl to 200, that will make the odds of a successful KS kill a lot less. Meaning, less chance of a solo kill. As the boosted player is probably dead by the next attempt.