I rather like to lead with an anti-bullshit Mandibuzz with Foul Play, roost, defog and knock off: it's very rare that The Man can't at least annoy the shit out of someone, he has the bulk to take a rotoms Volt Switch and Roost it off, it can take an Icicle Crash from Mamoswine and 2HKO it, providing it goes for the stealth rock mindlessly like most lead Mamos do...and there's very few things that appreciate a knock off. Not to mention it essentially hard counters lead smeargles. You do need to read the situation and get out of there if it's bad, but eh, that's what the rest of your team is for. I've also been finding Porygon2 with Eviolite to be a solid choice to push momentum in your favor, throwing out Tri Attacks or Discharges can get you a critical status, while dealing sizable bites of damage.