You guys will need motion detection in the woods. Fishing line and noisemakers etc. The number of people you need starts to climb dramatically as you add sentry posts. A good read for you is Failure of Civility and their reasoning regarding defense of rural versus urban settings. You will need point to point radios, plus more. Sneaky people will not use roads or paths once then know they are watched. I could hunt you in the woods and you would never see or hear me or differentiate me from wildlife. Rain and/or wind completely denies listening for noise as a means of detection.