A question about side rank

When generating your side info in your profile, you can choose a rank, from "ruler, caster, warlord, chief warlord". Since your side starts with only a ruler, is there any choice? Can I choose "caster", have my ruler be just a person, but still control him like normal, and just say that the first caster I pop is 'me'? This wouldn't affect how I played the game at all, just fluff-wise, I thought it would be interesting. Because otherwise it seems like you have to choose "ruler".

Might be a bit of a necro, but I'll explain this anyway.

The reasoning behind the options was that players might start play as a character in service of a side and slowly break of as a vassal and eventually a fully fledged side. Obviously this did not really go anywhere, but it definately is a fun thing that I might expand upon were I to redesign the rules.