Enchanter - Why bother breaking charm?

[Hamesh]

I understand pets eat 50% exp if you don't break charm. I'm not sure that it matters that much. My experience lately has been mostly on 2nd floor of City of Mist. Looking for someone to correct me where I'm wrong in my thinking.

Scenario 1:

Charm two mobs, let them kill each other, and nuke both for full xp.

Mez a pet (20), tash it (30), charm it (195) = 245 mana
Tash a mob (30) and send pet = 30 mana
Break charm, nuke pet (160), nuke mob (160) = 320 mana

Scenario 1 Total: 595 mana

Scenario 2:

Charm pet, give it weapons and haste, and let it go to town on slowed mobs.

Mez a pet (20), tash it (30), charm it (195), haste it (275), and give it weapons = 520 mana
Tash a mob (30), send pet, and slow mob (100 for Tepid Deeds) = 130 mana

Scenario 2 Total: 650 mana

In scenario 2, however, I don't have to break charm, nuke, and then charm something new every fight. Let's conservatively assume charm lasts 4 fights. I usually get more like 5-6 mobs killed before having to blur pet to heal it or re-charm due to break.

Over 4 fights, I tash (30) and slow (100) every mob so that's (4x130) 520 mana. I'm not purposely breaking charm or having to spend mana on nukes so I have my initial mez (20), tash (30), and charm (195) spread out over those 4 fights. Pet haste (AQ) lasts 24 minutes so that's about 15-18 fights (275 mana / 15 fights = 18.33) and costs roughly 19 mana per fight (19x4 = 76).

Scenario 1 over four mobs killed (2 fights, kill both mobs) is 595 x 2 = 1190 mana
Scenario 2 over four mobs killed (4 fights, pet kills all mobs) is 520 + 245 + 76 = 841 mana

The 4 fights in scenario 2 are also a hell of a lot faster. A hasted, weaponized pet seems to be doing well more than 2x the damage of an unbuffed pet.

So if I let pet steal 50% exp then I have to kill 2x as many mobs, but that seems to be easy enough to do with a hasted pet and I get 2x more gem drops etc from killing more mobs. Am I missing something?