Is it wrong to put "he ovat" here?
Well if you're answering then you should put the names, since this is a translation. If you mean if you could use it instead of them when speaking, yes, "he" means "they", so you would be saying"they are". I don't see why not.
I was actually thinking "he" in addition to their names, but that makes sense if their names already fulfill the role "he" would.
"Pronoun" means "instead of name", so you only need the pronoun or the name(s) :)