Structure for a strategy game

Question

I am making a strategy game like Age of Empires. It's a pretty big project and I need a clear game structure.

I have defined a Game_Object class with variables such as:

• Hit Points
• Speed
• Damage

• Range_Attack

• ...and a few functions to move the game object, load the game object to the screen, check collisions, etc.

Inheriting from this Game_Object class are:

• Building_Object (It is buildings in the game to train soldier and villager)
• Dynamic_Object (It is dynamic objects such as villager, soldier, elephant, bird

I have defined a Civil class, it is a class about the country. It contains:

• a std::vector<Game_Object*> GameObject containing game objects
• variables to store the number of resources
• a few variables about technology
• functions to check the amount of army units, villagers, houses
• a few functions to check collisions, update the game objects, move game objects

I have defined a Civil_Computer class, which inherits from my Civil class. It has a few functions to control the nation of the computer opponent.

I also have defined a Manager class, to load the map to the screen, load image, manage game objects, etc. It has std::vector<Civil*> containing the nations of AI and human players, a few function to initialize the game window, check winning, load game object to the screen, etc.

Finally, I have a header file to define many functions such as Move_Object, Check_Alive, etc.

Can someone suggest to me a clearer structure?