If you're putting human parts on anthro animals you're a moron. Learn actual animal anatomy or GTFO.
By that logic, the cow (Mary, I think? I'm awful with names) shouldn't have breasts, she should be flat chested with an udder, chew and vomit and chew her food, have actual hoof hands (or just hooves) and no opposable thumbs.
"Learn actual animal anatomy", oof.
It's a matter of balance, slapping an udder teat (with an extremely low-res normal map) on a human breast looks off, which is why most anthro artists try not to overdo it, or stylize the nipple so it looks good.
If it was up to me (and I know Elera lurks this thread), I'd tone down the nipple normal maps so it stops looking like Deadpool's cancerous dick. Besides, cow udder teats aren't so terrifyingly textured, they're quite a bit smoother than that, something most artists also tend to do when drawing/texturing cowgirl nippleteats.