Y'know, if you watch the first 1.5 seasons of TOS, what station on the Enterprise's bridge does what is a bit ambiguous. Yes, the guys in the front seat steer. The station behind Kirk is communications. Spock tends to do detailed analysis.
However, it's only in the last half of TOS that we explicitly start to get these hard and fast rules about who does what, down to Sulu owning the phasers and Chekov owning the photon torpedoes. They carried that into TNG, but it started to get untenable when they quit having a series regular at Conn.