Most companies, whether regular infantry or mechanized, or armored, have an incredible amount of firepower at their disposal. They cover a sizable amount of area when dispersed for battle and can be very versatile in their operations.
Most companies have two to six platoons and are led by an officer, an assistant (usually one grade lower) called an executive officer, and at least one senior sergeant.
Because fireteams, squads and platoons can vary so much, a company in one army can be completely different than a company in another army. For instance, a US mechanized platoon has four vehicles, a Soviet platoon only has three. However, in the big picture the Soviets have many more platoons than the US.
A lot of companies do not have certain organic weapons, like mortars, some do. This means that the availability of certain organic weapons can greatly influence how the company or battalion fights.
For example. A Soviet company does not have organic mortars so they must rely on higher authorities to provide support. This forces the company to rely on orders from the higher authority and can reduce the effectiveness of that company by discouraging initiative.
A US Marine Corps company does have mortars. Usually three of them. This allows the company to exploit an advantage without having to rely on higher authorities. It also allows the company to operate more independently and effectively on its own. While three mortars is not a lot of firepower, it is dedicated to the company and can provide immediate support until higher authorities can authorize additional support. Mortars also allow the company to deploy their own illumination and smoke rounds quickly which can greatly influence a battle.
When a company enters battle the company commander, like the platoon commander, will hold back a reserve. In a three platoon company this means at least one platoon will be held back, maybe two. When an advantage presents itself the company commander will deploy his reserve in an attempt to favorably influence the battle.
A company without a reserve can find itself in severe trouble if something goes wrong (and it usually will). The commander will have no one to reinforce a platoon with, or protect a flank that is under attack. For this reason, the bigger the reserve the better. Of course with the presence of a battalion reserve, the company commander may be more willing to commit his own reserve.
During a battle, the company commander must frequently rely on his platoon commanders to tell him what is going on. The company occupies a large area and it is not always practical to go to the front and see what is going on. A good company commander will go to where the action is so he can see for himself what is going on. Still, this area may not be completely visible to one man. The Company Commander and his staff deploy to where they can best control and influence the battle. If a Company Commander is firing at the enemy with his personal weapon he is nothing more than an over trained rifleman so he usually doesn’t want to be too close to the front.
In a ‘regular’ battle a company commander could theoretically command from the rear but more often than not the company commander will get close to the fighting. If the company has a weapons platoon, he is responsible for deploying it so that it will do the most damage to the enemy. This usually means breaking it up and dividing it among the platoons, but not always. For example. If the terrain is relatively open and the company is attacking an enemy on a hill, he might put one platoon and all medium machine guns on another hill so they can fire over the heads of the other two platoons as they attack. The company might even be assigned a few heavy machine guns from a higher headquarters.
The company commander has a great deal of responsibility because he has more troops and assets assigned to him. How he fights often depends on what assets he has and what his mission is.