Davion wasn't a terrible choice in my opinion (some of the worst politics, especially during the Fedcom/Civil War years, but good political culture). The FRR is cool, but barring a major historical upset, get trounced by the clans. Kurita's actions during the Succession Wars far exceed the level of psychotic on many, many, many levels, especially during the first, a combination with their culture that basically makes them
Clans light (and if I wanted to do the clans, I'd just take the full-flavored variety
), plus apparently they're full of sushi and hentai according too eyewitness accounts
Steiner... yeah let's just not go there.
So between Davion and the FWL, I liked the FWL's historical loyalty to the Star League, their political culture of granting high independence to their various realms, and the fact that, among the least objectionable member states (and again, I can be FWL without giving a damn about Marik; it's nice), ours
doesn't have some massive political snafu due in the next decade.