Relative to the elves, humans are goblins.

They breed way faster and live way shorter lives. In fact, the difference between elves and humans is bigger by many more orders of magnitude than the difference between humans and goblins.

Yet they seem to have somehow managed to work out peaceful coexistence between their races. The elves haven't exterminated the humans, and the humans haven't crowded the elves out.

I really have no idea why you think goblinoids would be any different.