I think a simple solution would be to add a "Defensive" tech tree, but then limiting your tech to 1 full tech tree and perhaps only lvl 1-3 of the others (bassically limiting them to only 3 tech buildings etc), this would make more of a tactical influence to the game, aggressive player? max your attack tree but you still get the first levels of the other trees, meaning you dont completely miss out on some needed tech in the game, Economic player? Max your economic tree and you still get some needed military and defenses, such as some of the frigates and some slightly better defenses, this could mean that the real advantage of a military player (aggressive) is that you get cruisers, while other players (defensive, economic) dont.
'Turtle' players will be most benefitting from this, as there arent much in the game at the moment that a turtle player can have compared to any other player, going defensive can mean that your defense capabilties are more balanced out with your assault abilities, better defenses but less ships compared to a military player, without making defenses tottaly overpowered or taking away a players ability to attack.
Personnaly I think it would be a really big improvement to the game at large by just limiting the tech a bit, in long games it is perfectly easy for players to get both tech trees maxed out, meaning theres not much point in going one way or the other, besides early advantages.
In response to the last post, I completely agree, but still feel this idea is balanced, 'turtle' players can get a good balance of defense and offense, but an offense player is perfectly able to overcome a turtle player, and vica verca, because a military (aggresive) player gets a much more powerful attack, but a weaker defense. An economic player can get alot more out of pirate raids and resources then other players, meaning he can probaly advance up the tech slightly more quickly, and can make alot more defenses and ships then the other players, but without having strenghs in one or the other, he will have strengh simply in numbers! Many, many, many ships could take out a upgraded fleet by simply outnumbering them 3-1, while the upgraded fleet could take out the larger fleet through tactics and sheer supreriority. While a balanced force of strengthened defenses and ships could be overrun by the sheer mass of an attacking fleet, but still prevail against them due to cunning designs in defenses and tactical defense positions, all in all I think this could easily be balanced out with a little work.
Also, culture would favour the defensive tech tree (or simply, the 'Culture' tech tree!) while the other focus on economics and military might, but still balancing the game out by letting any player push back a culture player's culture without damaging how effective or ineffictive culture is, basically making culture more easy to win a game with, but on the same token making it possible for a different type player to prevail over culture.
Lol, I said "In response to the LAST post" somewhere here, however the post I am reffering to is a couple posts up.