So what unit(s) do you go out of your way to get? Does it determine your rate and direction of expansion or do you send out an expeditionary force far from your lands to take a colony where you can build them? I remember back when I used to constantly be shipping Cretan archers and Scythian Riders to my legions, first as auxiliary's and then a continuous stream of replacements when needed. Lately I'm not sure if I've just become more practical or lazy but I've just started using whatever happens to be regionally recruitable in order to cut down on the logistics nightmare.