For the immediate future I still plan on creating the Great Hall and its upgrades and the Watch Tower.
In the end I hope to replace every single orc building with something else, that includes the altar, spirit lodge, totem and war mill as well, but for now those could be replaced by the Altar of Storms (WC 2), Temple of the Damned (WC 2), Orc Blacksmith and Ogre Mound already available here.