Are you perhaps Russian or Polish or maybe Czech? That's the only way this makes sense. No one else can have fun doing something so boring. No desire to insult, I'm just confused.
Yeah, you have a squad formed with the idea to split it up. I get it. I also have that, you could have 12 soldiers and split them into 2 groups of 6 or 6 teams of 2, or 3 4-man units or vice versa, you don't need 20 people. I will forget to move someone, or I will just stop caring. I sometimes have the trouble of not exiting the game when I need to control 8. 12 is really pushing it. If I had 20 soldiers, I would not even leave the craft with half of them, and would then leave half at the exit, and bring 5 to the enemy. I know what point you are trying to make, but I don't know how to explain to you that having to personally control 20 individuals is extremely boring, to say nothing of your plan needing the player to find all of the snipers, and all of the gunners, and divide them equally, and then slowly march to the ship, or whatever the target is.
And, yes, I know what base assault is, I played 2 today. Standing in the crossroad is a stupid idea, and it's much harder to defend than just a simple corridor, from where you can overwatch 2 crossroads.