More gathering units per supply
In the last general the optimal number of gathering units per supply source was 2 Chinooks , 2 supply trucks and 5 workers, for a supply building that was next to the supply source. The farther the supply building was from the supply source the more gathering unit you need. That is because in Generals a gathering unit can not gather while the other one is gathering. In fact i like that. But in order to rise the number the gathering time should be decrease. The amount of supply then is subject to balance.
I think it is better because it gives supplying mechanics a more important role.
If your gathering unites are destroyed you need more time and resources to build them.
Maybe is not so C&C.