You only really need a certain amount of AC to deal effective damage (except against high-HV charm opponents), but with mages getting insane amounts of LK, it might be worth it to have really nice base LK... The extra block early on is especially helpful (and even moreso if you leave shooting spree til after L7) since you won't be relying on HV much for those levels.
My own job3 lion is a 4141 LK scientist, and LK definitely still works nicely for the pure job3 lion. I never miss, I can still OHKO monsters, and all my gun skills crit like crazy.
Temp inactive again...
GigaBowser, 4411 HP melee dark/fire/lightning wizard, 193/204
Deudalephon, 4411 3:1::LK:WT melee water/lightning soul master, 150/165
Hemathion, 4411 3:5:4::WT:HP:MA melee dark lord, 140/140
Anchors, 1414 MA priest, 244/250
Vadise, 1414 MA wind/earth soul master, 210/216
IreneAdler, 1414 MA fire/lightning soul master, 154/152
So, like, let's go look for the road and talk about our hair!