Most RTS games DO NOT use polygonal models for their soldiers, units, tanks, etc. Most use 2D sprites. They may look 3D because many of the sprites are rendered from a 3D model, but they are rendered as 2D images.

Try converting all your soldiers into sprites with the number of sides you would need for each facing position. This will significantly speed things up.

80 models on screen at a time ... even very low poly ones ... will definately slow things down. I would guess this would even slow down the QuakeIII engine .