In SOVEREIGN, the setting informs the mechanics, which then energize the setting.

If you believe your character would be capable of doing a thing, they do it. If your Armsman should be able to tackle a Blackguard and subdue him, they can do that.

However, that Blackguard is also capable of defending themselves.

SOVEREIGN is not a game of System versus System. Its conflicts are Character vs. Character-based. There is no "GM Fiat" in resolution. Enemies are designed just like Characters are. This is a fundamentally basic RPG system. Your characters "Role" is what literally defines their actions. It's generalized, rather than granular.

The granularity comes from the experiences they endure, and their time enduring it.

If you start as an Armsman, they could become a Grizzled Armsman, a Scarred Armsman, or mature into something else entirely, like a Stalwart Commander, giving them access not merely to more capabilities and tricks up their sleeves, but even fellow soldiers and supporters to call upon in times of need. How your character is defined is up to you.