So this might just be my strange mind overthinking things, but I feel like the special zombies represent common problems/bad habits. Like
Boomers: Obesity- have you seen the size of those bitches.
Hunters: Assassins- they pounce on you from the shadows and tear you to shreds.
Smokers: Smoking- do I need to explain that.
Spitters: Acid- they SPIT ACID at you for fuck’s sake.
Chargers: Masturbation- their right arm is like 7572974 times the size of their left one. AHEM AHEM.
Witches: Depression- they walk around crying and moping. Not saying depressed people are as pissy as them, but you probably catch my drift.
Jockeys: Rapists- I can’t really think of anything else for these little fuckers. The way they ride on your back is just kinda rapist-ish.
Tanks: Steroids- there is NO WAY they are naturally that ripped.