Marian hegemony founding date is 2920, so 3th Succesion War time.
And how long was the Aurigan Coalition,
2910, House Arano - The Aurigan Coalition, page 11.
Randis,
The Brotherhood was founded in 2988, the planet is inhabitated since the time between the 1st and 2nd Succesion Wars, it was called Hope (and also Lost Hope at a time before Randis arrived).
Fronc
The planet was colonized jointly by the MoC and the TC in the mid-3050, the nation is from 3066.
or the Rim Territories?
The Rim Territories, a pirate nation, is from 3087. I think maybe Adacas is refering to the Rim Collection, that was created in 3048.