Ah, OK< another thing to blame on 4e then, cool.
If I may, this is a rather late source, for me Maglubiyet first appeared in the 1st edition Deities and Demigods (awesome source), and the subtext is quite different: " There is a whole host of creatures which have been created for the game of ADVANCED DUNGEONS AND DRAGONS that have either been spawned from the minds and myths of past man or created entirely from the minds of the game masters. Such a wide diversity of creatures and subcultures requires an equally wide diversity of deities and lesser beings of power. The nonhuman races occupy different places in every Dungeon Master's individual world. Therefore, it would be extremely difficult to create complete pantheons of nonhuman gods that would be appropriate to every campaign. This section seeks only to outline some major beings important to the races created in the AD&D family. A complete pantheon of all dwarven gods, demigods and heroes can be easily imagined, but its complete notation is too awesome a task for a work of this limited size (as would be the complete notation of the deities of any of the nonhuman races). Let this section serve as a springboard for the DM. It presents a start for any extensive pantheon that the referee feels he or she may need."
In there, he is a greater god, the rival of Gruumsh in power, not a lackey:
- Maglubiyet is a war god and a great general. He commands mighty armies of goblin spirits in Hell, where they eternally war against Gruumsh's orcish spirit army. (Goblin and hobgoblin shamans claim that Maglubiyet always wins these battles, but there is no permanent death in Hell, so the destroyed orcish spirits always re-form.)
- The orcs say that Gruumsh commands a mighty army of spirit-ores in Hell, and these war continuously with a similar army of spirit-goblins controlled by Maglubiyet. The ores always defeat the goblins, but the goblin spirits always re-form to start the battle again