Rough guide to comparing gear for Exenterator:
1.) "Line up" the two pieces of gear with the greater AGI piece on the right.
(6 AGI, 7 Attack 7 Acc) vs. (9 AGI 9 DEX)
2.) Cancel out like amounts of stats (AGI and STR) toward the right
(7 Attack 7 Acc)vs. (3 AGI 9 DEX)
3.) Delete any remaining STR from the left and subtract the (STR/4) from the AGI on the right.
(nothing to do here)
4.) Delete the attack from the left and subtract floor(Attack/3) from the AGI on the right.
(7 acc) vs. (1 agi 9 dex)
tl;dr Charis +2 is slightly better.
On top of that it's relatively common (at least in Dynamis) to do Wild Flourish --> Exenterator, or Evisceration --> Exenterator.