The civ should be a very nomadic people. Their buildings should work like the trebuchet in AOK, so you could pack them together, move them and unpack them again. All buildings would be created inside a town center, and you would have to move the carts you get from your town center to the desired location and them unpack them there. Their buildings would be weak, and the civ should not have any heavy fortifications.
An other important difference from the other civs would be that this civ would not have any villagers. They use their warriors to gather all kinds of resources. Their warriors would be weak, but you since you only have warriors you could beat your enemy with a huge army.
I would also like it if human soldiers could walk trough forrests, but of course siege weapons and big myth units would have to walk around. This could be a tech you would have to research, or it could just be another bonus for the civ. The downside about walking in the forrest would be that you could not attack from the forrest, but enemies could still attack you with ranged attacks. You would also get a reduced speed while walking in the forrests.