Modeler Variance Types

I have searched this forum up and down and I can't really explain what I am looking for, to a search engine . So I am putting this thread out there. I need to know how you are supposed to program model variance types.
I have seen it done in the SDK itself so I know It can be done, just not how.
What I mean by model variance is this: " i need to make programs so I can use models like google sketchup, lightwave, and other none supported models in the game. The way my team is set up is kind of complicated.
Each modeler likes their own modeling program and for good reasons too. I have seen amazing things that they have done with their own prefered modeler and then I have seen them struggle with another.
Idon't know why, but they do, I thought the modelers looked pretty much the same , but I geuss not. I think it is an animator thing. So it is in our best intrest to just make it where everyone can use their own modeler.
I have tried just exporting it through one common modeler but it takes forever, I have to search for the plugins that allow for that type of model, and then if they don't have it I have to get someone else to model the exact same thing in their model, which is hard because each person has thier own style.
So if anyone knows how please reply!