Maybe, maybe not.

We've seen Omegas take down WSs or shoot them up with their part cannons. Very small, harder to detect, faster and more manuverable targets. Though that was at closer range.

I do believe a Sharlin could tear up a Omega, but I'm certain she wouldnt come out un scathed, and maybe the fight would last long enough for another ship to flank.

Remember people, all it took were a few plasma cannon shots to damage Dukats ship and kill him. Imagine what a Part/X ray cannon would do if it were trying to drill deep into a sharlin.

Like I said above, I believe the sharlin would come out, but she would be damaged...maybe enough for another omega to take it if it is able to get the jump on it.