Morty and McGurk aren't differentiated and only named once, by O'Hare himself while he tries to take the seed from Ted's house.
They don't speak much in the film (though one of them said "Ooh.", when he bumped into O'Hare with the O'Hare van).
In the end, even Morty and McGurk turn against O'Hare, with the round-glasses wearing one of the two ejecting their former boss out of town by way of his rocket helmet. He is also the one O'Hare is seen with most frequently and perhaps is preferred over the other.