Create a new rule called “Focus” as follows:

Each Orc has a Focus, which is tracked in the GNDT and may be any one of the Stats, or (by default) nothing.

An Orc may Train a Stat by spending X-1 AP (where X is the Orc’s current value for that Stat), increasing that Stat by 1, and setting their Focus to that Stat.

When an Orc makes a GNDT dice roll to which one of their Stats will be added, and the Stat in question is their Focus, they may add +X to the total as well, where X is the number of Orcs who have that Focus.