Choices

the +def one is better because of the spd bane. res is also a superbane which hurts hector considering his dc capabilities

for ike go neutral so you can still make good use of warding breath

Yes, definitely +DEF because Hector will be beefy af with 44 defense, and 26 res is still pretty good for an armor unit. And he already has Vengeful Fighter and still ensure that the enemy will not survive his second attack. Just be sure to have some allies surrounding him if you don't want to slap on Wary Fighter.

Ike neutral is still pretty great for me. While -RES is considerably his best bane, it does decrease his chance of survivability against dragons and mages who double him. In the mean time, try to think if his Warding Breath is worth foddering off or merge or switch-a-rooni.

Ike: +Spd -Res. Even with Warding Breath, he struggles to tank multiple hits from mages. Plus, you can buff his speed to help him stop doubles from enemies.

Hector: +Def -Spd. Attack and defense are both good on him, but a speed bane is practically meaningless so you might as well preserve his resistance.

Go for the + Atk L! Hector he'll have 60 atk unboosted! And he leans more towards a mixed team with his Ostia's Pulse. Also, you have both super boon and super bane so you're going to have his 174 base stat total the same as if he was neutral IV, so no loss of arena points there. Just give an ally the Res Tactic 3 seal and keep them within 2 spaces of L! Hector and he'll get 6 extra res every turn, which will be easy to do thanks to baiting and distant counter. And if that ally is also his S rank support, L! Hector will be even more deadly when close to that ally. ^w^

As for L! Ike, keep both separate because neutral L! Ike gets used in a lot of free 2 play strategy videos, so you don't wanna lose him. Build the other one separately and give them different colored "fav hearts" so you know which is which. I pick blue for "free to play strategy vid" units so I can build the same teams used when I can't figure out how to clear a map/quest.

Finally, "wait and see" is always a good answer for questions about using resources in this game, cause once you fodder a unit they're gone for good, unless RNGesus loves you more than everyone else XDDD