you might need 10 total neck tails for the entire game.
it takes a whopping ONE tail to make SIX potions, and you don't need the potions anymore because armor negates poison mostly, so you really only use them maybe on the one boss that has poisoning. Even back before the armor change, 2 or 3 sets of potions were enough to do the whole swamp (the poison biome) . So 3 maybe 4 tops for potions and another 5 or so to eat before you discover deer, boar, and move on with your life. The minced meat isn't worth making, IMHO, but if you want to live off that its another 10 or 20 tails before you move on hopefully. If you have carrots, you really should have something better to eat.

That said, if you set up your home near a lizard pond, the spawns at night will kill them in bulk so you just need to walk out and pick up the tails now and then. I just burned 50 for coal and didn't kill a single one of those..