The hostage thing doesn´t make sense either since Weevil has no reason to care, but I´d rather talk about Fujitora vs Aramaki rn, not that
Greenbull was fighting hundred of fodders alongside King and Queen, of course he would use big AOE moves that cause destruction to get rid of them quicker then wasting time taking them one by one. While Weevil was alone.
But if destruction is so important, than the admiral that got killed by Xebec was either hostage diffed or nerfed too since there was no apparent destruction in Marijoa and we were even told admirals can't use their full power without causing destruction there.