Commanders require 2 Grandmaster Skills to be offered the respective abilities, for example GM Attack and GM Speed to be offered the ability to shoot on a level-up.
In Era only Master skills are required, not Grandmaster.
Skill descriptions, both in Era and in this vcmi mod also state that Master is the required level.
Tested on vcmi version 1.3.1 with WoG mod version 9.1.1.
Commanders require 2 Grandmaster Skills to be offered the respective abilities, for example GM Attack and GM Speed to be offered the ability to shoot on a level-up. In Era only Master skills are required, not Grandmaster. Skill descriptions, both in Era and in this vcmi mod also state that Master is the required level. Tested on vcmi version 1.3.1 with WoG mod version 9.1.1.