Best skills (Perks) for your Heroes?

[Zanatar]

I looked through the entire forum, and I do not see a single discussion on Skills (or perks) for your Heroes.

I noticed that on the skill page, for each Perk slot you get a choice of 3 Perks.

Is this random, as to what 3 choices you get? Or a set path?

I'd love to see a discussion on each char type, and the best skills (perks) to get for them.

Archer:
Knight:
Dwarf:
Fire Mage:
Ice Mage:

etc. And list the best perks to pick for them.

I'm asking too because there does not seem to be a way of reversing your choice, once you choose it. So I wanted to make sure I choose the right choices.

Thanks.

[Zanatar]

Can anyone take moment for this question? I would really like to get a better grasp of the skills / perks.

[freelancetom]

I prefer to follow upgrades in this way:
Slower fighters: Attack skills-HP or potion skills-defense-dodge-speed-resistance
Fast fighters (angels, amazons) attack-speed-hp-defense-dodge-resistance
mages-damage-mana-auras-dodge-resistance-defense-speed-hp (healing is a priority for healers, of course)
archers: instakill-Range-damage-dodge-resistance-whatever

Just have an idea for what you want to use each unit as. Slow tanks, fast strike, etc. Then plan accordingly with the perks.

[freelancetom]

My question is what the "finisher" skill does, exactly. It sure sounds impressive, but not sure what it's effects are.