Both being staff and also being on the field as a player, I can tell you that team work is essential to mission accomplishment in MILSIM. For the older players (those that have been in the sport a while) and the new players would agree with a "No kidding, Z." But honestly, we need to instill it in ourselves in order to relay it to other players.
Good MILSIM scenarios have an objective (OBJ) for that side to accomplish. Other wise it is a fashion show and deathmatch. Players that are new to TCA quickly realize that the OBJs are key and leaders are quick to remind players to focus on their assigned mission. Most teams and players bust their butts to achieve their assigned tasks, and after the first phase, they ask their higher headquarters and leaders about the bigger picture. Those that were initially in the dark as to who their leaders were or those that got separated due to having to respawn or through battlefield friction, use the time to find out the bigger picture. This sets the force for the next phase.
The Force and Company leaders over the course of several events have began to apply operational strategy to their force structures, and the staff has started to detect unit character (just like in real military units). I'll use Eastern Empire as an example, the Commandos and Airborne Regiment, though few in number, are quite capable, making the most out of their open weapon classes. They are focused and aggressive and but lack the "staying power" (able to sustain casualties) like the larger Rifle Companies. The Rifle Companies (CHAOS, DAGGER, and FIGHT) each have a personality of their own. Its awesome to see many of the same TCA players sign up for the same companies over the course of 9 years. CHAOS Company lives up to its callsign, chaotic in its attacks, disrupting Western elements, but the chaos works against them as casualties mount, often having to do one of the hardest tasks, that of attempting to reorganize itself while in contact with the enemy. DAGGER, sharp at the tip, and along its advance, can penetrate towards an OBJ, but has to rely on CHAOs to protect the hilt of the DAGGER, otherwise it can get flanked and surrounded. FIGHT Company, lives up to its callsign, focused on an OBJ and does well, but is usually the smaller of the Rifle Companies and can lose OBJ focus due to the fight in front of them. Western Forces elements have a similar character, and it wouldn't be fair if I didn't go into theirs here.
Task Force Darby and SOF, though small in number, are mission focused. SOF often gets onto the OBJ but has to rely on friendly forces to link up in order to maintain gains. TF DARBY, is molding into an assault force, when the two specialty units work together, the results are awesome. ABLE Company is a formidable defense element, quick to adjust to flash FRAGOs, BAKER is similar to DAGGER, a good penetrating element, but needs flank security or company leaders to direct replacements to maintain gains. EASY Company takes on mission sets without fuss, and can sometimes over commit themselves similar to FIGHT Company.
The Faction Command Teams are realizing these unit personalities, and are starting to incorporate this knowledge into their strategies. Knowing who you are fighting could provide something of value. Knowing your OBJ and the strengths/weaknesses of your unit can assist in the individual player in understanding how they fit into the larger picture/strategy for their side.
Going back to teamwork, both at the leader level and individual level, is why the TCA Staff consider MILSIM a sport.