I personally absolutely hate the idea of incorporating non-Dragonlance setting-specific races into a Dragonlance campaign. It'd be like the Forgotten Realms stealing kender and tinker gnomes ... erm, whoops, they already did. But that's just me.

Anyways, if you were to incorporate warforged, one approach would be to make warforged unique. A singular invention that was the culmination of a gnomish life-quest, the creation of a sentient machine.