Putting yourself in a set strategy tells you exactly what you are supposed to be doing at the time without question. You are only responsible for a portion of the map instead of all of it, so you get to what you have to do and where you need to be faster. When there is a lapse in communication, your role is still clear.
If your team needs energy, and everyone goes out and hacks generators all at once, what isn't getting done?
If your team needs deploys, which deploys are the priority?
If your team is all attacking, hacking or defending, who is providing communications on the enemy movements you aren't seeing on your screen?
If your team is all rangers and one tech, you're hacking slow. If you're all techs and a gunner, you don't have top speed and have problems destroying vehicles/deployables at a distance. If you're all gunners and a ranger, you're very slow for all the firepower you pack. If your group that "understands what they need to do at the time" works without balancing out who is doing what, you set yourself up with inherent weaknesses.
A set strategy isn't like a linear path; its like zone control. While the opposing team may understand what your particular responsibilities are quickly, that doesn't corrolate to knowing exactly where you are going to be and what you will be doing at any given moment.
You can take the totally freeform solution and maybe go places with it, but the strategy I outline is a basis for successfully playing the game against most opponents (taking skill out of the equation, because you can never adequately factor in for that; less skilled players will beat out more skilled players in this game at points due to the limitations imposed by the class system). For players getting used to the tactics of the game and playing on the pubs, it gives them a better sense of roles that need to be filled. For players preparing for match games, it outlines what positions need to be covered and what a player should be doing in that position to be successful.
Good luck all, and see you in the game.