Problem with spawn object of Client

Hello everyone! I'm developing my Final Qualifying Work for a university. It's a mobile multiplayer-game which contains all data with help Google Services (save/load/refresh) and doing connections by UNet servers. And on my final step to complete project I've found very annoying for me a problem: we have 2 clients while one of them - it's the host-client. Player have class which contains array of prefabs. Every prefab of every player have specific values of variables: power, health points, speed, strong, cost etc. When we playing host-client spawn own prefabs without any problem: if own prefab have 20 strong points - in the game that prefab will be have the same value of strong (20 points). But if client want to spawn own prefab (for example, with 50 strong points) - server will spawn server's prefab (with 20 strong points). Generally: client can't to spawn own object with own values. What to do, guys? Until the 16th June I must to solve this problem.​

What was I doing:

• Was trying to get object by GetInstanceID(). I was getting this ID, client getting this ID too but as before I can not to create (to spawn) object of client;
• I can't to spawn object which we got as parameter from signature of a method with attribute [Command] because in this case client will be throw NullReferenceException;
• We can't to spawn object with [SyncVar] too;
  
• If we change attribute of our CmdinstantiateObject() method from [Command] to [Server] than only server will can to spawn own prefabs;
• Was trying to registrate prefabs in OnStartClient) on each client - without any result;

Hopefully anybody can to help me!

Code (CSharp):

1.        
2. [Command]
3. private void CmdInstantiateObject(Vector3 pos, int _currentUnit, int _money)
4. {
5.      GameObject objectForInstantiate
6.           = Instantiate(_units[_currentUnit], pos, Quaternion.Euler(90, 0, 0));    
7.      NetworkServer.Spawn(objectForInstantiate);
8. }

 

Guys, anyone know how to help me?