So I've actually had a few chances to test Lairon, and I have to say, first, it can't pull off Heavy Bomber. However, thanks to my switching of sets/abilities, I figured out Rock Polish Larion can actually put a dent in quite a few things, especially because, with Sturdy, you can survive a hit on one of those crippling x4 weaknesses and still live (bar entry hazards).
Fun facts:
-Lairon can utterly destroy Shanderaa, as it can survive a Fire Blast or Overheat with plenty of health and OHKO back with Stone Edge. And god forbid they're locked into Shadow Ball, you can get off three RP's and still be at >1/2 health, then proceed to bust Shanderaa and continue beating up anything not packing Mach Punch or Vacuum Wave (it will survive several hits of any other priority move).
-Trick Room teams love it when you switch in Lairon, because with no speed investment it can outrun most everything under TR and resists many of the common types TR teams pack (Psychic and Ghost).
-Paired with Balloon Desukan (pretty non-standard, but it beats up Dory for you with Mummy and burn from WoW, so what's not to love?), which is immune to both of Lairon's exploitable weaknesses, you can switch the two back and forth to cover each other's weaknesses (as mentioned before, Lairon can soak up Ghost and Dark moves until the end of time, even from something as powerful as Shanderaa) while burning and Hazing everything that moves. Shadow Tag Shanderaa trap-kill Desukan with Shadow Ball? Good, Lairon gets to set up free.
-Ditto doesn't have Sturdy, so anyone foolish enough to switch Ditto in on Lairon will most certainly die, while you hang on through the Scarfed Earthquake.
So, that's kinda it right now, it's been pretty good in practice, thinking about adding some sort of healing support to the team so I can abuse Sturdy and get rid of burns (which hurt Lairons already barely there sweeping capabilities). I'll post the set if anyone cares to take a look (or, y'know, you could search it in the usage statistics somewhere below Starly, and take the set from there, because as far as I can tell I'm the sole Evo Stone Lairon user).