They are considered so untrustworthy and underhanded by the other Orcs and goblin races that they refuse to have dealings with them. However, they are employed by the Chaos Dwarfs as their slave drivers organizing other goblin slaves. The reason for the close relationship with the Chaos Dwarf dates back to the Black Orc revolt when the Hobgoblins initially marched with their larger cousins but soon betrayed them to the Chaos Dwarves and so gained their trust.
Originally Hobgoblins in the Warhammer Universe were inspired by the Mongol empire - the hobgoblin miniatures produced by Citadel therefore had a decidedly "eastern" theme much like the Nippon miniatures that Citadel produced at the same time. Though the theme is quite Mongol, the Hobgoblins do not seem to wage war on Cathay or the other Eastern states as the Mongol Empire did.
It is also interesting to note that the first incarnation (i.e. the Mongol inspired one) had hobgoblins with a brown/orangish coloured skin tone whilst the second incarnation (referred to above) changed the skin tone to the more common green hues employed for all goblinoid races in Warhammer.
