The sentence in question is the lsat one of the paragraph. I think what's meant isWaving the clubs in their hands, the orcs were obviously angry. There was a fire, which meant humans were nearby. They were enemies, and the fire was a bait. Watching this, Tabitha considered which spell she would use. There were more enemies than she had expected. She couldn’t continuously fire spells out. If they didn’t carry everything out smoothly, they could lose their advantage easily by a surprise attack.
If things did not go according to plan, they would lose their advantage after the initial surprise from their attack. (They would be at a disadvantage once they lost the element of surprise.)
Can I have confirmation on this?