Management can be wrong about many things, but this doesn't mean that the "hired gun" as the OP says has to come out swinging.

A job is not an object, a human is not a machine.

You can be another Nero. Come, burn everything down, and leave, or you can be a compassionate with people, talk with everyone, win minds and hearts and accomplish the same thing.

I worked with both kinds of people, clashed with the first even if we were trying to accomplish the same thing, and cooperated with the latter, even if what they wanted is complete opposite of my views.

I behaved that way, because the former one wanted to do the job, get the praise, and get me fired in the process, but the latter one showed me an outside perspective I failed to see, so I agreed and did whatever I can to fix what's broken from outside perspective.

If the first person didn't see me as a threat to themselves, I'd have pushed them to the place they wanted to be, because I'm no ladder climber, but they don't work with us anymore.

Of course there will be stubborn people to do whatever they can to protect themselves, their position or whatnot, but they are rare and generally have other motivations, from my experience.