A contributing factor was that the Finland-Swedish-speaking actors were better trained, and the language variant had finally been accepted.
history
способствующий фактор
Фактор, который способствовал результату, о котором идёт речь.
European Theatre Migrants in the Age of Empire
This collection examines the journeys and working lives of European theatre practitioners during the age of empire. Historical case studies explore migration, performance, cultural exchange and the political conditions shaping theatrical careers across national borders.