I agree there's not one simple "right" way to do almost anything in Elvenar (other than possibly bulding boosted production buildings once you have the relic boost unlocked and some relics working, that seems pretty universal).
For my part I don't craft the evolving and other buildings that I don't want early on because they take up spell fragments and CCs that I don't have before I start hitting the Spire in chapter 3. I might not even have a Moonstone library set if there hadn't been the Spire glitch that allowed me to win a complete set in the Spire. I also don't use a lot of military buildings early on (haven't needed one yet), so even though they don't come around as often I am able to build up a substantial inventory (currently 12 MMMs, 15 UUUs, and 11 ELRs). I get the theory behind crafting buildings to remove them from rotation, but I haven't had the need to do it yet.