Ah, there's that influencer populist data again. Besides what
@Type-IIx said, why would the fact that compounds are from the same "class" of drugs make combining them useless? They are still different drugs and thus have varying pharmacodynamics. That being said, some effects might be additive, like for instance; the antiestrogenic effects of mast and primo, if you so chose to combine them, is definitely an important factor ... But not all effects are the same or similar, so you still need to know each drugs individual mechanisms of action irrespective of their "drug class".