You are using the US legal framework to understand a Swedish situation
In much of Europe striking doesn’t limit to refusing to work, but can be refusing to do only certain tasks or refusing to do them only for a certain client
In Sweden it is legal for the workers of a company to strike in sympathy with other workers at another company with the caveat that they can’t strike completely but can refuse to do work that would benefit the company the original strike was against
You are using the US legal framework to understand a Swedish situation
In much of Europe striking doesn’t limit to refusing to work, but can be refusing to do only certain tasks or refusing to do them only for a certain client
In Sweden it is legal for the workers of a company to strike in sympathy with other workers at another company with the caveat that they can’t strike completely but can refuse to do work that would benefit the company the original strike was against