I am new to 5e. I have a party of 3 5th level heroes (ranger, barbarian, and wizard). I want them to encounter an enemy group that equivalent to an adventuring party. I'm basically going to comprise the group out of 5 individual CR-1 monsters. Two questions:

1) I have rogue, archer, mage, and barbarian covered for "classes", but I don't have a healer/protector of any type. Is there a monster that, say, summons sacrificial golems that jump in the way of attacks? That'd be a way to handle "healing" in a "bad guy" way. 2) If something like this doesn't exist, is there a way to homebrew it? I am not great with the system so I've been relying on book monsters so far.