No, you build up two blocks. Because it’s smol, it shouldn’t be able to hurt you, while you can hit it or shoot it with your bow. Plus, maybe it’ll drop some of those diamonds.
No, how its done is put the baby zombie in a 2 blocks wide hole, fill it with water, and when it turns into a drowned baby zombie the armor will come off and you will have unused diamond enchanted armor (unless you hit the baby zombie)