For my campaign in the Annürien Marches I needed a goblin army (in 15mm of course). I already had trolls and ogres (by Magister Militum). I had to trade goblin minis (by Ral Partha) with Jérôme (who has tons of them). Most of goblin infantry is weak (CV3, AC2) so you need to group a lot of them. Goblin only have light cavalry (mounted skirmishers by Splintered Light Miniatures) but fortunately can be supported by troops which cause terror (trolls and ogres).