If one spawns they should all spawn, however the center is probably the worst ARK map ever made, with holes in the terrain and a redwood biome that will even delete your tames at times, with some animals spawning below the world or so high its in the skybox. Unfortunately we tried fixing all of the maps problems in the past, but its 100 percent the map. I would recommend turning the primeval spawns up in the ini settings to assist.