If you combine all profitable EA into one EA. Do you think it will be more profitable?

 
never
 
If you are sure 100% that your EA is profitable, then, why looking for other EAs?
 
The poll doesn't quite make sense for me...
 

One strategy say sell and the other one say buy.

so the result is not the same.

 
Profitable only if you have enough balance and proper money management.
Reason: