The Swiss and the German leagues can keep their own and are also attractive to foreign players (including Finns and Czechs), whereas the Finnish and the Czech leagues rely on fresh production from the juniors and returnees on their last legs. In the past Finland could still compete for quality foreigners, but in recent years it has increasingly become just an alternative to Allsvenskan. It doesn't help that both have more teams (15) than talent either - that even though there's also a Finnish team in the KHL and a Czech team in the ICEHL.
I think Erik Thorell, currently the best foreign player in Czechia is quite a decent example. From his native Sweden he went to Finland as he wasn't good enough to make the SHL and subsequently dominated the Finnish league. Then he moved to Switzerland where he wasn't good enough to earn a new contract. And now in Czechia he's again one of the very best in the league.
I think Erik Thorell, currently the best foreign player in Czechia is quite a decent example. From his native Sweden he went to Finland as he wasn't good enough to make the SHL and subsequently dominated the Finnish league. Then he moved to Switzerland where he wasn't good enough to earn a new contract. And now in Czechia he's again one of the very best in the league.