The workers are ai controlled, while the players can perform the tasks of the workers its better to have the workers do the mundain tasks. You also for the most part have to research a lower tech item to get the higher tech stuff, all sorts of requirments to build something or research something. So you cant just go for 1 thing, have to atleast get the stuff along the way.
I find that often when I command I will totaly change a strategy based on what they are comming at me with, as having differnt techs can provide differnt types of towers that work better on differnt weapons, and such. I also base it off the people who are playing, some weapons are better for newer players while other weapons can be deadly if you are skilled in it. So knowing your troops can give you a nice early advantage.
Anyways, I cant wait to get the fresh blood in game and see how games develope. Should be quite fun..