In RL it is quite common to have few separate cores near by under the same big cloud - we often successfully circle at different areas under single cloud and observe each other to after a short while move under the fastest rising glider, so while good separation between clouds and their thermals would be desired it would be wrong it it would result in single thermal core per cloud.
This would be even more pronounced in cloud streeting where line of “cloud thermals” should provide enough lift near the bottom of elongated clouds trail (one mostly touching another) to enable traveling for tens of kilometers without alt loss.