Well I got to re-reading this and I realized that I posted a supporting fact of my argument, but I failed to explicitly state what I was trying to convey: It's what we call in the (US) military, METT-T. Mission, enemy, time, terrain, troops. Advantages are dependent on a number of factors, and I'll cite examples given I don't confuse this with a salute report like I originally did.
Mission. Usually combat oriented, but Eden has a distinct advantage in Space Race.
Enemy. What's your enemy doing? Granted, you can't ever be completely sure, but it's one of those skills of being able to read what they're trying to do and thusly, adapting.
Time. Obviously, Plymouth has an early advantage. After that, the other factors start carrying more weight.
Terrain. Depends on map and respective positions. Anyone have a favorite Pie Chart (the original) starting position? Many old players did based on their playing style because there were very subtle differences.
Troops.I played a high intensity, 3 vs 3, 6 hour-8 hour (hard to remember exactly how long it was), game that was non-stop combat and missle launching (I cite this particular battle often because it was one of my most memorable). 2 Edens, one of which was me, and a Plymouth vs. 3 Plymouths. Although the hours long stalemate was broken with Thors, it could have well been any weapon. They were lynx that simply avoided massed units, and were quick to evade missles. Until then, everyone was mass producing Tigers which are easy targets to missles.
In short, you make the best of the current situation. Although I was well known for rushing, I thouroughly enjoyed a long team game because it often times pushed tactical and strategic considerations. I've seen the most interesting maneuvers, ruses, and counter attacks by even the simplistic players. I've even surprised myself a few times.
It's all how you play your hand.