Well, it's not that hard to reduce the polycount when the model is textured.

You just have to weld some vertices on the mesh and then, under the Edit UVW Map modifier, weld the UVW vertices that are broken after the poly reduction.

Let me show an example

We are going to weld the 4 vertices marked in red




When the vertices are merged, the texture looks texture, cause the UVW vertices are broken




Just Weld the broken UVW vertices and voila!