I guess it's leftovers, then. I actually have something else for Mawile, as it can SD to break through Avalugg. I find rocky helmet just doesn't help in the matchups I'm using Avalugg for, like Lando, Garchomp, and Kyurem-black (earth power and HP fire do more than fusion bolt). Pinsir takes damage from rocky helmet, but it usually isn't a determining factor (avalanche OHKOs if attacked).Rocky Helmet is usually better on Avalugg for it's ability to get continuous chip damage on Pokemon like Mega Mawile that normally threaten stall teams while you're using recover against them as they attack, meaning you aren't forced into attacking nearly as much. Leftovers is also a solid item that prevents you from being knocked out of sturdy from sand or misc chip as well, it's just a bit less consistent against specific mons than Rocky Helmet is.