only build them one at a time. Build and trash until you get a good Infantry center. x 75/75 + After that you can build a second RC in the same region. Costs more depending on number of RC's so its cheapest to just burn through a bunch one at a time til you get a good first RC.
Unless of course you pull off an awesome Cav or SF or range 4 Archer center. Then keep that and then repeat the process by building a 2nd RC then trashing it and rebuilding it til you get a good Infantry center.
If you are going to be facing a lot of Rogues you may want to consider going for a good Range 4 Archery center to start with. I always build random centers and don't bother building specific centers. Its way cheaper and in my opinion more fun.
If you are really lucky you'll pull out a decent range 5 SF center. HD has them now, but the original Morek managed to build 2 nice range 5 SF when Dwilight first opened with identical stats. One was in Caiyun and the other was in one of the Rurals. The lords of those regions did lots of forced drafts and a significant portion of Moreks early army was range 5 SF. You will need lots of archers if you want to defeat large groups of monsters. Archers make them retreat quickly and then you have to fight them for several turns in a row as they keep rallying and dwindling down.
