Mechanics wise, it'd make Recon unbalanced in general; recon can already be very respectable fighters on the defensive, have naturally higher movement, and are the greatest class for invisibility advantages. Pillage would make outright conquest by force needless; send faster groups of recon to pillage the countryside and destroy the other person's economy, and the economic advantage would be ridiculous even without attacking cities.
You can do that with melee, but they're slower. You can do it with horses, but that's sort of their big purpose.