What I said applies more to things like props that are instanced many hundred times onscreen. For instance if you build a house that uses the walls from one model and the roof from another and you simply use both textures instead of combining them into your own. In SF terms it applies to 3rd party cockpits that often source from the "stock" gauges.
Anyway as for optimizing performance, there really exists no point in having a model with a resolution higher than, say, 1000 tris at distances beyond 1-2 miles in this game. You can whip up the final lod in an hour just by modeling around the highres mesh but keeping it free of all unnecessary detail.
Just trying to be helpful here, that's all.