What are Sachie-Chan and Jiya?
Jaco the Galactic Patrolman,
Jiya, and
Sachie-chan GOOD!! are part of the
"Galactic Patrol series", a collaborative narrative expanding the world of the past by primarily establishing "background information" for the Galactic Patrol through short stories taking place before the beginning of the
Dragon Ball manga.
Jaco the Galactic Patrolman, which is the furthest chronologically, is the most significant of the three,—introducing the character of Jaco, Tights, and (physically) the Galactic King; linking directly with and including the
Dragon Ball Minus: Departure of the Fated Child story, which established the current iteration of Bardock and the world of Planet Vegeta; and directly linked with the
original manga,—but
Jiya establishes the character of the Galactic King and the asteroid threatening Earth, which he is confirmed to have destroyed in
Dragon Ball Super (albeit, only in the
anime), and the Galactic Patrol's idea of Earth being in its developmental stage, which is referenced in
Jaco and in
Super, is derived from a false report made by Steth, the main antagonist of
Jiya; and
Sachie-chan GOOD!! introduces the species from which the Galactic King originates and the suits of armor characters like Jiya, Steth, and various Patrolman appearing in
Jaco and
Super are equipped with.
Admittedly,
Jaco the Galactic Patrolman is effectively a soft reboot of the "
Galactic Patrol series", with the modern series only ever referencing the
concepts introduced in the former two stories, rather than any of their specific characters or plots, but nothing suggests they were ever
decanonized.
And do they have any relation to indexing abilities or feats/scaling/cosmology here or nah?
Jiya confirms the number of stars in the Milky Way galaxy,—approx. 200 billion,—and
Sachie-chan GOOD!! establishes Japan
did once exist in the Dragon World. In the grand scheme of the
DB World, though, they are self-contained stories taking place decades prior to the
original manga.
Given they were intended to be short stories set in the
Dragon Ball canon with an interconnected narrative through the Galactic Patrol, with
Jaco the Galactic Patrolman indisputably being canonical, I see no issue with including the two in the blog—and even creating pages for Jiya, Yukio, Steth-Vamp, and Sachie.
At worst, they are
soft canon, which I am 99% certain is a synonym for secondary canon.