It's who is going to lead that team.
In WWII, it was one thing to say, "You, take 2 men and set up an OP 50 yards to the east. Send a runner over if you see anything" and saying "You, take 2 men, conduct an extensive recon in that general direction, defend yourself, take any objective you can, and make a whole lot of decisions on your own", or something to that effect.
Independent operation of a fire team isn't going to be able to do a lot of complicated things without a leader that is well versed in everything they need to do.