The underlying reality that makes universally accepted evolution in this game so difficult, is that the games "war" structure, scoring and perk system drive different behaviors, based upon different priorities for many players. This can be a good thing, if each of these behaviors compliment one another, whereby accomplishing one priority also yields success in the lesser priorities for each player. On the other hand, this can be a bad thing if choosing one priority requires virtually forsaking success in another. This game can't be all things to all people all the time, but opportunities to make it more things to more people more of the time certainly exist.
Consider: (these examples are in my no means meant to be all-inclusive of either types or reasons)
If you're measurement for success is rank, then the game's ranking system discourages high risk behaviors that are critical to winning the "war".
Why up Buffs to sink a heavily defended CV that is attacking your base, when you can milk run a few towns for 10 times the damage points? After all, even if you get attacked by 100 guys and shoot every one of them down from your tail gun, those kills won't count towards your rank, yet dying in the puffy ack counts against it.
As a fighter, why would you engage in any fight in which you didn't have a significant advantage? Upping that field under heavy attack is high risk behavior that offers no advantages to your rank, it's much safer to just let that field go, and grab 20k and look for the next unsuspecting and often irrelevant kill to the "war".
Why would you run supplies, man a field gun? No rank improvements there.
On the other hand, if you're objective is to win the "war", the game encourages you to avoid the fight.
Why let your opponent see you coming on a base take? After all, if you sneak in NOE and smash and grab the town your chances of taking the base are much improved, and the only shots fired are likely to be against AI ack.
Why stay up to fight the leftover and late defenders after you take a base? They're unlikely to post any threat to recapturing the field, so it's best to just ignore them and look for the next undefended base.
Why turn and fight that LA7 defending his field? He'll just re-up and offer more resistance to your capture if you shoot him down, it's better to just drag him away for as long as possible and draw out as much of his ammo to give your troops time to sneak in.
And then of course, there's the pure "thrill of the fight player", looking for that co-E, co-Alt, may the best man win fight, who is frustrated by the won't engage me w/o a huge advantage "Rank" player, and the "avoid unnecessary conflict" player intent on winning the war.
AH needs to focus it's evolution on giving these fundamentally different types of players a reason to engage one another. The "Rank" driven players enjoy a good fight and winning the war too, the "War Winners" would certainly enjoy a higher rank and a good fight, and the "Thrill Seeker" would enjoy both winning the war and earning rank. The problem isn't about the things we all love about the game. The problem is that many of the things we love about the game require us to give up a little of something else we love to obtain it.
I believe that one way (In addition to many of the above great ideas) to bring these priorities closer together is to better align the priorities of winning the war and earning score/rank closer together. This seems to me to be a rather simple first step.