First, I do have a little experience dealing with armed marijuana growers, as where I live (Humboldt County, CA) is probably the center of the cultivation industry in America.

I have noticed a couple things when I've had to deal with these types. First, they try their absolute best to avoid you. Second, they are not really likely to have weapons on them (while they love to have a stockpile in their camp for whatever reason), or when the weapons are on them they are not fire-ready (not cocked, not easily accessible, etc).

One thing that has been pretty consistent with confrontations in the mountains is the "pack" method of intimidation. I've gotten into some less than desirable situations with a group of guys, and know a few people who have been robbed by a group of guys (one guy was then jumped and beat up).

I don't see a firearm as escalating a situation, I see it as leveling the playing field. I am pretty competent with my handgun. You're right, against a mountain lion I may not have a chance unless I was aware of it before it attacked. I have caught a mountain lion trailing me before, and if it attacked I would have had time to draw and fire... even if I missed the simple noise may have been enough to intimidate it.