I think that's spot-on, Alan.
I mean, just look at their history. They started out on par with the other Clans in terms of forces and holdings, then they contracted post-Wolverines/post-Widowmakers when they lost their Albion and Homer holdings, then they expanded out again under Khan Ceana Boques with new holdings on Foster (and making their first new friend in Kindraa Smythe-Jewel, which would continue on with the Mandrills after that Kindraa fell), then contracted again because of the constant Burrock raids on Foster's supply lines, then spent a period of time treading water and being unable to grow because of the constant predations by the Burrocks, then they traded WarShips for Mechs with the Snow Ravens and built their touman up (by the time of the Burrock Absorption, the Spirits fielded twelve Galaxies), then the Absorption War happened and the Spirits' touman was shattered by the Burrocks and Adders, then the Spirits took total control of York and retracted again, then they got involved in the Wars of Possession post-Great Refusal and started expanding again (including the establishment of their hidden colonies in Colleen), which continued on into the Wars of Reaving where they were probably the most active and expansive they'd ever been, then they retracted again after devastating losses in the WoR (most egregiously the Adders' genocidal destruction of York) and Viper Annihilation... and just as they were starting to climb out of the abyss, the Adders returned and finally finished them off.
Writing it all out like that, it sounds almost exactly like that game.