Two surveys put the same senior engineering job 14% apart. Which do you believe?

We take part in two surveys for technology roles. For senior software engineer in the Netherlands, one gives a median base of about 86,000 euros and the other about 98,000. Same level on paper, both with decent sample sizes.

I am at a payments company with around 1,100 employees. Until now we have simply averaged the two, but a 14% gap makes the average feel like a number that describes nobody.

How do you decide the weighting between sources, and do you ever drop one for a specific job family?