Possibly, I don't think we can really tell either way. We've seen both dispatch lesser enemies with ease. K'sellis may be dead, but he always did the eating.
He managed to think through how to deal with Noe. He was smarter than Grem for sure, and probably the rest of their group. At least I thought he was pretty smart; gave good advice and had a quick wit and most of the off the wall things he said were to mess with the goblins.
I think K'sellis vs Switchbeast would have been a to-the-death scenario. That's how you dispose of your unwanted slaves, it doesn't explain how you subdue them in the first place. Point is they apparently have ways of hunting down strong prey other than feeding them to monsters.
Although I'm just griping really, this is more the way I would like things to go than the way I expect them to go.