Using absolute numbers that is true. However, not when you look at numbers per million or population density.
Not only is population size a factor but populations density too
United Kingdom: 432.16 per million population death rate and populations denity of 281 per Km2
Belgium is 693.74 per million and density 383 per Km2 - so their higher rate/million is no surprise, comparatively
Spain - 544.22 per million and density of 91.4 per Km2 - so their numbers are high both for population and density measures using the UK as a baseline
Italy - 481.19 per million and density 206 per Km2 - so their numbers are also high both for population and density measures using the UK as a baseline
And there are countless other confounding factors!