I generally really dislike the "the character was just being retarded" argument. Saying she didn't use ACoC because she underestimated them is writing the story for Oda, he hasn't made it clear that was the case at all so that's just speculation. Also, if someone is on your stomach with a sword in your chest, clearly charging up an attack that'll destroy your internal organs, I'd kinda doubt she'd just intentionally not use ACoC because, eh, they're weak I don't need to.
Also why would the homies need to be verbally told she needs saving? Either the silence was pointless and the homies were just out of commission (from being cut in half), or it makes no sense - the homies have been shown to have a will and mind of their own after all.