Are ‘surat gereftan’ صورت گرفتن and ‘ettefaaq oftaadan’ اتّفاق افتادن (to happen) interchangeable?

They are synonyms and sometimes interchangeable, but there are differences – as is the case with most synonyms. For example, surat gereftan صورت گرفتن is more formal than ettefaaq oftaadan اتّفاق افتادن . Also, surat gereftan صورت گرفتن has an element of volition/planning in it. We can say: Haadese key ettefaaq oftaad? حادثه کی اتّفاق افتاد؟ ‘When did the accident happen?’, but this sentence with surat gereftan صورت گرفتن is a bit unnatural; or in the sentence: Entexaab-e modir-e jadid baa deraayat surat gereft انتخاب مدیر جدید با درایت صورت گرفت ‘The choosing of the new manager was done wisely’, ettefaaq oftaadan اتّفاق افتادن doesn’t fit well.