I have a L30 Slugger. "Power Hitter" is better than "Wild Swing" because your ability to knock back larger tanks takes away the main defenses of hordes.
L30 Fire Chief (3840 hp 324 dmg)
L30 Slugger (2421 hp 94 dmg)
So a Slugger is no where near as "tanky" as a Fire Chief. But their ability to deprive a horde of its defense is supposed to make up for it. I'm tempted to level mine to 40 just to boost its deployment cooldown (you regenerate them faster).
I have to admit, it's also fun to see Morticians/Undertakers get knocked back away from trying to resurrect zombies!