Which strategy to take depends on the starting conditions and win conditions, as well as how your randomly generated deck is distributed among build tower, build wall, attack enemy tower, attack enemy wall, increase resources, and decrease enemy resources cards.
You go for the "maxed resource" win when you start with decent tower and wall, and the win condition for tower building is very high. The AI is very bad at winning under these conditions because it doesn't seem to be programmed to save a particular resource.
When the tower win condition is low, however, you run a high risk of the enemy completing his tower before you, so you have to prioritize building your tower and tearing down his, whatever the cost. You go for the "completed tower" win. The AI is best at winning this way.
When the starting conditions have very low tower and wall, with very high tower building and maximum resource requirements, you are best off to concentrate on defending your tower and tearing down his - you go for the "destroy enemy tower" win. The AI is moderately good at going for this kind of win.
Sometimes you have to change strategies mid-game if you realize that your deck is stacked towards a certain card type, and the enemy deck seems to be stacked toward another card type, that makes winning by your original strategy unlikely.
Post edited June 24, 2011 by belgarathmth