If the body was big enough it would have completely erased the earth’s crust, after cooling again our current crust would be a mixture of both bodies. Having a

If the body was big enough it would have completely erased the earth’s crust, after cooling again our current crust would be a mixture of both bodies. Having an outsized moon might also degrade the orbit of any material that would have been left over after coalescing into the earth and moon.