AR vs JAH

[Ombra]

First of all, thanks for helping.

Get what Im saying?

I thought yes. But it's no.

but go into single player and mess around a lil.

Yep. Doing it.

I'm making a MA sin with dual-claws, for PvM only.
Currently level 91, Act 5, Hell, Base STR 75 and DEX 150.
With equipment: STR 180 and DEX 273.
No relevant charms.

Claws are 2x Bartuc's with Jah.

It's a custom build I'm making, for fun.
Short story:

FoF and CoT are set to 14 Skill points. BoI is at 13.
Phoenix Strike at 20 (for synergies).
Claw Mastery at 20.
Main finishing move is Dragon Claw (DC), 1 point.

My AR with CoT is 11594 (on both claws).
AR with DC is 15867.

Merc is:
Act 2 (Defiance aura), with Infinity (Conviction).

In combat I cast Cloak of Shadows, of course.
But even so, I have a hard time to hit most Hell monsters.
In some extreme case I've been swatting flies for 2-3 seconds before landing a hit!
(Target was not frozen).

Last place I fought in was the Icy Cellar. Found packs of Champion "Pit Vipers".
It says my chances to hit a Pit Viper are 91% (with CoT), and 93% (with DC).

My AR is not exactly poor.
And I got Jah'ed weapons.

Do you know why it's being so difficult to hit stuff?
Thank you very much.