>>15105756fire fang from salamence (252 atk) on skarm (252 hp/252 def): 28.1% - 33.6%
fire blast from salamence (0 spatk) on skarm (252 hp/252 def): 76.5% - 90.5%
skarmory won't do anything to salamence, so durability isn't relevant. area traps are deadly (stealth rock/sneaky pebbles/etc) and will wreck you in the long run
if you really don't want to risk not hitting with fire blast flamethrower (61.2% - 72.2%) is also an option
smogon suggests these moves not because they're elitist faggots (which they are) but because they're the most effective