The Murlocs have, as per usual, low defense, and take a lot of damage

Level 36-4o martial empires gold grinding guide - The Naga on the islands in Desolace have low armor, and there are casters in the mix. Be wary of the wandering sea giants, though. One will walk across the island every now and then, and they'll kill you if they see you.

The Murlocs by Grom'Gol in STV are excellent grinding. They have, as per usual, low defense, and take a lot of damage. Some casters mixed in the fray as well.

In the Badlands, there are a lot of rock elementals. They range from about 37 to 42 or so, if I remember correctly. They're sort of close to the Horde base, so Alliance might be weary of the area.

They die fast, and they have some pretty good vendor drops. Higher level ones spawn by the Ogres camp, and have a chance of spwaning Rumbler, a named rock elemental. There's also a few quests right by the lower ones, so some extra experience and Warcraft gold is fun.

You won't need an important factor to enter it, so don't concern yourself with that. You'll need an organization with a healer and a tank and any DPS you may get in the online game.