As for other monk damage outputs, currently that unarmed wisdom based Monk 20/Divine Champion 10 gets:
2d10 (Unarmed)
+ 1d10 (Blazing Aura)
+ 4 (Enchantment Bonus)
+ 1d6 (Fiery Fist)
+ 4 (Strength modifier with Belt of Growth)
= 28~
If they take the Northlander Hewing feat:
20 (Unarmed maximised)
+ 1d10 (Blazing Aura)
+ 4 (Enchantment bonus)
+ 1d6 (Fiery Fist)
+ 4 (Strength modifier with Belt of Growth)
+ 4 (Northlander Hewing bonus damage)
= 41~
Now, if you make entirely strength based Monk 30, you could get the following damage per hit:
3d10 (Unarmed)
+ 10 (Strength modifier)
+ 4 (Enchantment Bonus)
= 30.5~
And with Northlander Hewing it becomes as follows:
30 (Unarmed Maximised)
+ 10 (Strength modifier)
+ 4 (Enchantment bonus)
+ 10 (Northlander Hewing bonus damage)
= 54
Truly, a strength based monk's fist hits like a truck. However, it comes at the cost of AC, as you can see from below:
10 (Base)
+ 1 (Luck of Heroes)
+ 6 (Monk 30 AC bonus)
+ 3 (Tumble)
+ 4 (Dodge boots)
+ 4 (Armor enchantment)
+ 4 (Deflection echantment)
+ 4 (Natural armor enchantment)
+ 4~ (Wisdom modifier, with +3 or +4 item)
+ 4~ (Dexterity modifier, with +3 or +4 item)
- 2 (Northlander Hewing AC penalty)
= 42~
I suppose you could cross-class into UMD and use Shield Wand for +4 AC, but it doesn't change the fact that for a large part of this monk's career, the AC might feel way too low.
And I did not mention this previously. But a fist based monk needs that gauntlet/glove slot for +4 Enchantment Bonus. A quarterstaff using monk can use it for something else. For example he could wield those +4 Dexterity bracers, or +4 AC bracers that in turn frees their chest slot for something else.
As for:
Steve wrote:I could imagine a new Feat like Combat Insight, where for Staffs, Wisdom REPLACES Strength when using a Staff.
What would you call it, Combat Intuitiveness?
An Aasimar Monk 20/Divine Champion 10 could be assumed to reach wisdom of at least:
20 (Base)
+ 7 (Ability increases)
+ 4 (Divine Champion bonus feats)
+ 2 (Regular epic feats)
+ 3 (Wisdom item)
= 36
That is a modifier of 13, which becomes +19 damage on a quarterstaff. Therefore, a wisdom based monk would be dealing avarage of 24~ damage with a regular mundane quarterstaff.
Thus the quarterstaff damage output would become:
2d4 (Quarterstaff)
+ 19 (Wisdom modifier)
+ 1d10 (Blazing Aura)
+ 4 (Enchantment Bonus)
= 33.5~
It would be superior to what an unarmed monk with a similar build can achieve, with or without Northlander Hewing. Northlander Hewing reduces number of attacks per round, alonside the -2 to AB and AC, thus our quarterstaff monk could just leave Greater Flurry of Blows active and pile on the damage. While being able to use Cold Iron and Alchemical Silver quarterstaff when needed, and having that glove slot for something more beneficial.
Edit:
I think it would just replace wisdom based unarmed monks with quarterstaff based monks.