It's a viable method, you just won't be able to kill them. They'll have question marks above them until you're around two or three levels below them. You won't be able to deal any damage to them, and they'll be able to one shot you. Just wait for now.

There are three total Hive majors below. They are level 18. Still, it's one of the best spots for farming Hive majors if you ever need to. There are other good spots for this as well, including where you land on the Moon two boomer majors are past multiple Fallen enemies that wait in the central surrounding. On the same planet if you head toward the chamber where Phogoth waits in his strike, two boomer majors can always be found waiting. There actually used to be an ogre and various other Hive waiting in the opposite direction. Then the game introduced Fallen in that room (this was during House of Wolves). Now the chamber's empty. Three boomers can also be found on the Dreadnaught when entering the passage leading toward the Darkblade strike. At your level I'd probably say it's too soon yet to even attempt tackling much of anything. I was on Earth in the farming spot several hours ago. There was a level 3 player that went down below... and died. I went down there and cleared the Hive, while the level 3 followed attempting to shotgun the enemies. However, my melee attack is much more powerful than anything that spawns on Earth... except of course for things that can't be dealt with in that way such as the Fallen walker and Taken bosses.