But the editors can't and shouldn't be expected to correct the stat blocks. That would be like expecting a textbook editor to know more math than the mathematics professor who wrote it. An editor is the person who corrects grammar, spelling, word choice, readability, and the like. That is what they are expected to know--not monster statistics. They aren't hired because they know all about DnD, they are hired because they are experts on the English language (or what ever language in which the book is being published).