Back on topic, what other early bombers were there?
Early war Brit bombers besides the Wellington (11,461 built):
Handley Page Hampden (1,430 built)
Armstrong Whitworth Whitley (1,814 built)
The three of them were the mainstay of RAF bomber command until the four engine heavies (Avro Lancaster, Handley Page Halifax and Short Stirling) became available in large numbers.