Honestly... I agree those look fine for ingame models. However maybe actually using a smaller resolution texture (currently there are multiple 1024x1024 maps, right?) might help. After all on a typical screen the model is maybe 500x500 pixels in total at maximum, so the engine has to combine a lot of texels into one on screen pixel. A sharper 512x512 texture would thus maybe look better in game than what you currently have, without loosing any real texture detail on screen at all.