Would combining the class results give a smaller deviation from the expected?

Combining class results can often lead to a smaller deviation from the expected outcome due to the averaging effect, which tends to reduce the impact of outliers and random errors in individual classes. By aggregating data, the variability can be minimized, resulting in a more stable estimate. However, this is contingent on the classes being independent and having similar distributions; otherwise, the combined results may not reflect a smaller deviation.