Potential is the opposite of Real. Real is related to Fact. Detail is a type of Fact. 
Crucial is a synonym of Excellent. Excellent is the opposite of Poor. Poor is a synonym of Remote. 
Potential <--Antonym--> Real <--RelatedTo--> Fact <--IsA-- Detail 
Crucial <--Synonym--> Excellent <--Antonym--> Poor <--Synonym--> Remote 