Previous studies showed that two swarms of autonomous robots pursuing two conflicting goals can cooperate efficiently, especially at small swarm sizes. In this study we investigate how the spatial separation of the two conflictive aggregation spots affect the cooperation behaviour. The swarms are controlled by the BEECLUST algorithm, which is a robot control algorithm inspired by honeybee behaviour. We found that the spatial separation of the optima does not affect the aggregation efficiency of swarm sizes of 9 individuals or more. In contrast smaller cooperating swarms take advantage in their aggregation efficiency. Heterogeneous swarms are a big challenge in swarm robotics. When several tasks have to be achieved in parallel, swarms have to split up in task-related sub-swarms. Then efficiency enhancement by cooperation and the exploitation of side effects are a successful recipe for developing swarm intelligent algorithms.