Sith Trooper's (aka Larry) basic ability "Sith Strike" has an underlying damage range of 12756 to 14089
Whereas Omega's basic "Disarming Shot" has an underlying damage of 6751 to 7461
At Gear 13, Sith Trooper has a baseline of 4472 Physical Damage from gear
Omega has a baseline of 3553 Physical Damage from gear
It's clear they didn't get the numbers right. She doesn't get any turn meter or cooldown reduction mechanisms like other attackers and at 150 base hero speed,with a 3 turn cooldown on Adaptive Learner, she's just too slow to get going.
Not to mention you miss out on the benefits you get from using someone else in the 5th slot, like Rex, Shaak Ti or Gideon.