I've seen some magnetons lurking around in NU, so escavalier isn't exactly the safest option, even if it decides to run drill run. Escavalier's recovery is pretty much limited to a rest sleep talk set, not sure if people run that or not. It's probably decent but you miss out on pursuit trapping. If it doesn't run rest, then linoone just needs to wait around until escavalier is 50-60% to set up, which is pretty doable.
Mismagmius is an option, but it has to be running timid, and it can't be running a sub cm set or else it will lose. Linoone can always run jolly to mess up haunter as well, although I imagine jolly linoone will miss out on some kos. Both ghost types are also prone to pursuit trapping, although not sure how prevalent that is.
Defensive normal resists have existed in every meta where linoone was banned, so I wouldn't say that's a compelling argument to me on why it's not overpowered.
Crustle/amoonguss/tangrowth/armaldo/golem all fall to the flail set you love so dearly, although flail means you're giving up seed bomb, which probably doesn't matter too much anyways.
Sturdy users could work, but unless you have fairly dedicated hazard removal, stealth rock/spikes/toxic spikes will most likely ruin any plans with sturdy. Also it seems like you're forgetting that linoone is usually the last pokemon revealed in the match, late into the game, so the odds of someone keeping a sawk at 100% throughout the entire match on the off chance that the opponent might be running linoone, is pretty slim. My main issue with linoone is that it has a +2 priority stab extreme speed, which makes it very deadly vs an offensive team. You might think, oh if I'm running offense, then linoone won't have a chance to set up, but that's generally incorrect, unless you run 6 things with fighting coverage or strong stab moves. An offense team can't just rely on a priority user or a scarf pokemon to deal with linoone, unlike other set up sweepers, which can be dealt with scarfers or +1 priority.
We're probably not going to take any action with NU currently since we're still ironing things out in OU and UU before we really touch NU, so whatever can go wild in NU currently.