2 Crol
I'll answer point by point, but first, a small digression. For me, Creature Ability (CA) is a myth and nonsense, so I don't care what skills lead to it; there are much better options.

Leadership – is inspiring really more useful than a speed aura??? o_O I disagree. Tactics, plus an aura (and even plus boots with +1 speed) means that almost the entire barbarian army attacks from the first turn.

Defense – it can be useful against attacking units (rangers, infantry). But otherwise, it's not worth it.

Attack – why are you so categorical? Apparently, because you play with CAs. Nevertheless, this is the most versatile skill for a barbarian. Only tactics are almost beyond discussion and should be at 98%.
a) Fire Arrows, if you're rushing with machines.
b) Retribution in the late game with morale (which is 100% because an orc 100% needs leadership).
c) All three basic skills. Although, only if you're playing as Garun, because he initially has ranged attack, which isn't very useful for an orc. Also, ranged attack with Hagesh, but it's debatable.
d) Again, for Garun and Hagesh. Battle Balance and Retribution, but it's a pity to sacrifice Tactics.
e) For Krag, choose Stun and Retribution. Because doubling the damage from a hero's attack is nonsense (the stun is more important) compared to +25% to the entire army.

Luck – what searches are you talking about? It's a waste of levels. Luck at +3 is enough; we only pump perks if there are free levels. Against mages, you need resistances. And Soldier's Luck... well, who does it work for? Maulers for the second strike, but they're not even taken. Earth elementals for spells on hit, but it's not that important. So, it's a questionable skill to spend a level on, especially at the beginning.

Battle Orders – a skill at 2%, that says almost everything. Of course, casting spells a little more often is nice, but not enough to spend 4-6 levels on it.

All the resistances (not just Chaos, which is generally nonsense to take against the League) are very questionable. There's no benefit if you don't guess (and 100% options are basically only Darkness against Lethos, and Necropolis can be Chaos against Sinister), but spending 6 levels, especially in the early game, is a death sentence for your build. And if you take it later, you might not have time to level up.

Well, and in general, the main thing is, WHERE IS LOGISTICS??? This is the main skill for a barbarian, along with Pathfinding.

I didn't mention machines. It's just a skill for a fast game, and it's mentioned in the attack section with fire arrows; otherwise, it doesn't make sense. And in general, there are many ways to counter machine units now, and it's useless in the late game anyway, so it's a very, very questionable skill. Creeping is more fun with it, but six wasted levels can really hurt in a rush or anti-rush.