Kozov,
When we say Bais Shammai was not the majority, that means that the majority thought Bais Shammai was wrong!
If we knew being sharper meant you were always right then we would always pasken like Bais Shammai and we would always pasken like R’Meir. But we don’t. The future Bais Din HaGadol which will have the ability to best discern who is right, will examine each issue on its merits and pasken like Bais Shammai where they were right and Bais Hillel where they were right.
To take the statement literally is just illogical.