But is it not possible for the talented graphics modders out there to creat such 1 to 1 representation?
I don't know how complex this would be, but at the moment it is not possible to edit the models themselves as the file type is 'proprietary' to HWLG. JMM has mentioned putting together modding docs/tools, but that this has to wait for other, more pressing things to be done.
The current models also look to be pretty basic so how much they could be optimized I don't know. Then if you change the models, you'd have to look at the animations. The terrain (trees, grasses etc.) and buildings would also need to be scaled. Given the constraints on zooming and angle of view in HWLG, how this would all look would be anyone's guess. I'm imagining that the ground textures would need to be simplified so that the units wouldn't be lost against them.
And none of this mentions the computer resources needed to run the game with effectively 10 times more models. It would certainly be interesting to push it and see, but I don't think it will be a quick job.