That argument would make more sense if they did not include Poland, the biggest per capita spender and a staunch US ally.
The US doesnt treat any of its puppets particularly well. America treats its European allies a bit like Moscow treats its Belarussian ally. With the new administration that is becoming clearer than ever.
While the US can exert a lot of influence, Poland (and others) are not puppet states-- there is no direct US control over government/elections, no dependence on the US for those governments and no US control over polish law.
Being a weaker member of an alliance does not make you a puppet.
Meanwhile Italy is allowed to buy chips with 1.5% defense spending.
It doesn't make sense to think that defense spending is the criterion used to select the countries.