I think that planet choice drives faction choice, not the other way around. Also, players can set up a second base in a different faction and then switch their HQ to it. So I don’t think faction selection is as fundamental as race selection at all.
Are the devs really not going to implement company creation on mobile? That seems strange to me given the amount of effort they spent on the mobile UI. Who was that for, if not for players who only want to use mobile?