I did a mix, with Xerolco 01 through Xerolco 19, with Xolotl Prime as my capital. These are the 19 colonies that fit around my homeworld's regional government.
As management is dull, I don't plan on expanding past this for the moment. I'll build my planets, then when I'm ready I'll send a ton of arcs to colonize the edge of the galaxy, just for the sake of it.