Just to hit this again, I want to re-iterate the importance of safety in this kind of training. When you go from your own advanced individual training and move into the realm of basic team training, the danger goes up exponentially. Guys in the military train with their teams on a daily basis for months, sometimes even years in the upper echelons. There is a certain level of trust and commitment (not to mention competence) that permits this level of training to be done safely. When you are doing this on your own, oftentimes you are missing this depth of institutional training and awareness. You are thrown together with a group of strangers whom you barely know, and are expected to perform safely as a team, within a very short time span.
Back in the stone ages, everyone was a vet. So there was a common bond there, even if you just met the guy. Nowadays, you get guys with all sorts of backgrounds; some with a clue, who work hard at learning to be a team player, others who are so arrogant they refuse to cooperate. Then you have the instructors. Some are very competent at what they do, or did. Some are gifted teachers. Some are even both. So you have a very big challenge of trying to impart the basics of team training in a very compressed time line. If you have some background in the subject matter, you will probably be able to come up to speed. If you don't, you will probably not be able to do this stuff on your own, without direct supervision. Even with all the buffoonery on line, as seen in other threads here, I'm surprised more people are not seriously hurt or killed in shooting accidents. I won't call it training. That being said, there's no reason to temp fate yourself.
If you are going to attempt small unit tactics training, I would highly recommend going to someone that not only knows their stuff, but can usually teach it safely as well. That usually means someone from SF. If you look at Mosby's book, you will see a goldmine of training templates, which have been used very successfully to train everybody from goat-herders to arf-comers. I think this crawl, walk, run progression, (actually dry, blank, live fire) as used by the US military is probably the best template for success in this sort of training. There are others who do different things, but in general, this is the template I would use.
Beyond the basic formalized training you may do, we get into the realm of follow-up or continuation training. Here is where you truly learn the stuff, by getting the reps in. It takes a team of guys with a lot of dedication and hard work to get to a basic team standard with, you guessed it, safety. And this may be the hardest part of all. It's hard enough on your own; with just 4 guys, it goes up to extremely difficult. But definitely worth all bullshit.