I think fun by definition is an individual concept. Exp, some folks have fun kicking baby puppies, some enjoy letting out stress from a hard day by goofing off with their friends, some like recreating history and creating a community that is effective at achieving its goals. Whatever "your" goals are, there are plenty of regiments that fit into different levels of the extremes. I think the only trick is finding the right regiment for you.
My personal thought on the matter, though, is that you can't have lasting fun in our LineBattling community without some discipline. The linebattles themselves have rules, which automatically requires some base level of discipline.
Think of it this way; those guys that chatter the entire time in TS and screw around in-game and horseplay. YA, they get to have their version of fun. But what about the guys who want to be the most skilled warriors in their regiment? To claim all the kills, show off their merit and be a star? And what about the guys that want some peace over the air-waves to hear the orders and focus on their surroundings and excel at the game as well, but maby on a more company-level rather than individually? And then you have the historically minded folks, who enjoy a more serious reenacting environment? To them, being more serious with the game is fun. But without good command and discipline with moderation, all these types of players can't exist together. The goofying off fellows and warrior-rambo guys break orders to get their last shot off, to chase down the straggler when the officer orders the line to reform, to jump out of formation and try taking on all the circling cavalry on his own, which in turn causes more men to follow him out of formation? The players trying to be more immersed or take a more serious approach are at a constant struggle with the loose and even somewhat chaotic fellows, calling one side "Too uptight" and the other "Trollish and annoying".
It's up to the self-claimed commander to decide whether he wants to create a regiment that entertains one side of the spectrum or tries to moderate. From my experience, a regiment of moderation can actually help folks mature on a personal level. I've known goofy troll-like fellows that joined our regiment, and instead of angrily quitting on account of some discipline requirements they didn't like, they stayed(Or were allowed to stay) and maby calmed down a bit, worked with the officers and other players at a semi-bearable level, maby even sparked an interest in the operation and effectiveness of the company/regiment. Other folks who joined seemed to get a nervous break down, shouting at folks to quit messing up the line or head-bobbing so much, or chatting over the orders. Some of those folks stayed too and maby learned a little endurance and patience with the other players.
The other category I mentioned before would be the "rambo-minded" folks, which is what I was(sorta still am), in combination with the historically-minded as well. The rambos of the regiment like to break orders to achieve more personal goals on the battlefield. But my rambo-complex was at odds with my joy of history and actually helping the regiment look and BE the most damn awesome regiment we could be. In a sense, my desire to show off also led to a desire to help the regiment I was in show off. So ya, I was one of those folks that liked to get the men to follow orders effectively and look fit, capable and keen. I think everyone can have the most fun as a whole when there's moderation and some discipline involved. It's like a sandbox game, in a world without a rules and you can be god, life can get pretty boring without goals to follow.