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Well, it's clear that you need a lot of mana, but something will always be lacking. You can't have everything at once. Education is a powerful thing, I'm not arguing, you can pump up basic skills quite well by level 30, but with constant luck, it's much easier to break through enemy troops, and besides, you don't have to carry artifacts for luck and take up an extra slot for other, no less important artifacts.
The funniest thing is that I completely messed up with wisdom. I accidentally took the "Unstable Mana" perk instead of it, and only noticed it a couple of turns later. Well, never mind, as you already said, there's always not enough mana. Next... about magic reflection, well, agree, it's still better than when 100% damage is constantly dealt to you + with Arcane Wave + Chain Lightning, and don't forget that there are often artifacts on the map that reduce damage from each element of chaos magic. I don't know, it's a matter of taste, but personally, I'm very annoyed by Warlocks and Mages with their offensive magic, especially when the enemy has a tiny army, and he hits you with Chain Lightning on 50 units and runs away. That's why I always take resistance and reflection against Warlocks and Mages.
Regarding logistics, I only once played some map from the campaigns without it and regretted it very much. I still like it when the main hero runs a lot and far, with the condition that the enemies are cowardly and often like to run away from you, this is extremely useful. Well... so far, no one has beaten me up in the first week, I'm also playing on a hero, I got to the 3rd mission, and that's where logistics is very important.
PS I didn't know about the 100% damage bonus, thanks for the info!