Comparing data sets with different measurements
You're right, you cannot directly compare the scores, since they are extracted from different samples, using different metrics and parameters, etc. Is exactly as comparing apples with airplanes.

But is not so wrong to play around with the placement in the rank: you are comparing placements with placements, so it makes perfectly sense. If Sweden is always at the last place, this definitely means something.

Maybe you can also think of weight those placements by some parameter/set of parameters which takes in account the subject of the ranks.
As example, seriousness of the threats (ex. infection by AdWare can be less important than identity theft, etc), coverage of the population by the authority which published the results, reputation of the authority, etc.

You can also extract uncertainties on those ranks, maybe based on the statistical samples taken in account by the authorities, and so on.

Cheers