The other players you see in SFH2 are bots, or computer-controlled players. Due to the game being offline, you are forced to play with bots with kinda smart Ai Code. Note: Not everyone has the same bot behavior as me(Bry6543). Look at the bold letters below.
-Bots crouch normally to get better aim.
-Bots use melee weapons properly
-Bots can collect medkits and armor, etc. (But seem as if they don't really know that it is in front of them, and must be forced to collect them.)
-Bots stay in the range they are supposed to be in, like a sniper shooting at long range.
-Bots know how to use all weapons correctly. Like when to press the fire button repeatedly and when to hold the fire button.
-Bots know how to navigate the map.
-Bots aim fair.
-Bots seem to not have any means of pathfinding, as if dynamic or moving randomly. (A exception is that they do not intentionally die of environmental death, like the disposal beam in Isolation of which they stop and wait until the beam disappears, at least if no enemies are close to the bot, which suicides in a attempt to backpedal and shoot.)
-Bots can be killed by jumping over them while shooting below you while the bot is crouching.
-Bots do not actively do objectives rather then just stand there to wait for the player or another bot to come to it's area. They do objectives when the player is at a reasonable amount.
-Bots do not see through walls, which makes sense to avoid the bot from going either crazy from too much targets to handle or to be extremely overpowered, such as Wall Hacking sniper bots.
-Bots do not defend the player or other bot, rather sit there and look at you carrying the flag that they wanted to get.
-Bots use killstreaks in a instant when they reach the kills needed, further wasting the killstreak.
-Juggernaut Bots normally hit themselves when using Zeus, Flamethower, Corbra, or Nitrogen Gun, especially Mercenary Bots with rocket/gernade launchers.
-Sniper Bots are just overpowered when they have actual snipers.
-Bots do not kill much, requiring the player to do much of the work.