I mean, yeah, certainly the individual members of any group are wrong. Even liberals as an entire group can be wrong. But, the liberal position I'm talking about isn't the mix of all the views liberals hold, I mean the established positions that liberals as a whole generally hold. When the general liberal position and the general conservative position differ on a point, the liberal position is almost always more closely aligned with the facts. That isn't because liberals are smarter, more rational or better informed necessarily, it is because liberals as a whole tend to be deciding which side of an issue to take by looking at facts where conservatives tend to pick a side based on ideology. For example, the liberal position on a given tax might be that they support it because it will reduce inequality and inequality is bad because it has effects A, B and C, and because they believe the impact of that tax on growth will be minimal, as found in studies X, Y and Z, and so on, while the conservative position might oppose the same tax for purely ideological reasons that don't depend on factual claims at all. For example, they might think "people should keep what they earn" or that "taxes are theft" or some such ideological stance.
Pragmatism isn't necessarily inherently superior to ideology. But pragmatists are definitely more aligned with the facts, since that is the material pragmatists work with, where ideologues work with ideological principles.