I have a separate idea, which I was going to make a new thread for, but it fits here. Make the Warg Sentry buildable on the small defensive plots around the base, along with the sentry towers, and nerf it so that only 1 warg patrols the base per sentry. This would not only make it useful, but potentially superior to the sentry towers. It would probably have to be somewhat more expensive than the sentry towers to balance it, but this would add some great diversity to Isengard, as no other evil faction has more than 1 option for the defensive build plots.