Any vehicle can be stolen. Is the H3 easier than any other vehicle? No! Look at the last generation of Chrysler Jeeps that could be joyrided by kids in less than twenty seconds.
All the relays, switches, etc., will do nothing if there is a tow truck waiting for the vehicle.
The passkey system works great to deter probably 60 percent of possible thefts, but switching ignition modules (which is not easy), adding other relays, etc., will NOT stop the professional. (Switching the so-called CPU on a H3 is not the answer. The passkey is contained within the BCM, and the BCM is not just a switch and play. The BCM is what recognizes a key, and sends the ok to the PCM to fire the injectors and close the relays required. It requires programming to recognize the vehicle, and BCMs cannot be swapped between vehicles as was standard in the old days with older systems.)
A viper is great for letting you know if some kid or inexperience bozo is trying to steal the vehicle, and great for letting you know if someone is breaking in. But honestly, if they want it, and they are pros, they will get it, and I don't lose sleep over it. I carry good insurance.