Against Lugia, C or SE?
Talking about Tyranitar and DPS
Stone Edge has more DPS in a vacuum but only if you can fire enough of it to make it worthwhile. Crunch is more reliable in most cases.
Against hydro pump I suspect SE will be substantially worse, as you'd struggle to fire 2 SEs, against SA maybe it's even but I don't see a substantial advantage of SE over C.
But if you're on either SE or Crunch it wouldn't be worth using a TM though if you are short on them.
Pbbblt... T-Tars may become glass cannons against hydropump but they’re still viable. They’re just not as potion-efficient. If you got the pots, you’ll have a better chance of nabbing an extra damage ball with them then without them.
But if you do use them against Hydropump, they pretty much have to have Crunch because you’ll never get off an SE before you pass out.
I've found that Crunch performs better for me than Stone Edge against Lugia, even when Stone Edge is weather boosted; I generally get 4-5 Crunch's off per Tyranitar, and 2-3 Stone Edge's. And the last SE normally comes with a dodge or two, where with the Crunch, I'm not dodging anything.
Caveat being that most of the Lugia I've been running into have had ES/HP or ES/SA, with very few double psychic movesets. (or Dragon Tail for that matter; I've caught more DT Lugia's than I've battled) Maybe if I had the double-psychic, I could get more SE's off (and SE has been weather boosted here regularly), but that hasn't been an option for most of my raids.