The covid response did not depend on the opinion of a single person. The FHM is responsible, not Tegnell. This was clarified early during the pandemic (somewhere around May maybe?). The director of FHM essentially told everyone during the press conference that it was very shameful of "some people" to paint Tegnell as the sole responsible for "the failures of the swedish strategy". An example here disproving the "crazy scientist Tegnell myth" is that the messaging remained exactly the same even when Tegnell went on vacation during the summer.

Also, it's even more complicated since FHM don't have authority to tell other government institutions how to run their business. You could call them a governmental support function, if that helps.

Regarding that Swedish politicians are "free dumb" and "they can't do anything". We have laws that could impose lockdown in the event of war, but these laws do not apply to a pandemic/epidemic. My understanding is that Norway and Denmark have similar laws, just that they do apply to pandemics/epidemics. I don't think it is right for politicians to have the ability to lock up people when the law does not support it. We should have had a law that could be used during a pandemic but we didn't.

I also think that the asymptomatic carrier thing is more complex than you describe. I don't think a majority of the cases were from asymptomatic carriers and if you follow the recommendations (social distancing + wash your hands etc.) it wouldn't be a problem.