Rol, the damage isn't divided by anything =P.
The switch axe has A Lot of power same like the GS. The issue is that there are 3 types of damage factors in the game.
Each works differently on the different parts of the body.
Now each type will hurt period, but let's say it Angakator was knocked over and you hammer his back you will do a lot of damage to that part of his body but not really contribute to the whole damage. While if you use SnS or GS there you wont be hurting anything really. The difference is that the point of what you intend to do. Slashing weapons are more made to take out the underbelly and leg's of a monster (tail also).
Piercing weapons however breaka lot of the monsters shell/hide so while a Switch Axe would need to first mame that part of the body before dealing real damage or have high affinity the lance will only need 1 spot to keep poking at.
LS is probably the most obvious for this. The sword will do no damage until the body part is wounded or the sword is charged.
Anyway you can really test the damage by stunning a deviljo to hell then unload at max sharpness and affinity the charge from the Switch Axe. It would only take 6 shots from the Ala Switch Axe to send it limp.
GS is much of the same, I've seen people 3 hit kill a Kurropekko on the full charge swing with the above method.
I should also say that you should do them in Jho's face.
The raw damage formula for Monster Hunter Tri is:
[Attack Power x Type of Weapon Strike x Sharpness x Hitzone Multiplier x Special Class] / [Weapon Class Multiplier] = Raw Damage
Weapon class multipliers are as follows:
Switch Axe: 5.4
So Rol is totally right. To calculate the damage you divide the formula by the Weapon Class.
PS: Nobody answered my Question for the 3 Star arena quests. Has nobody tried them?