Did less political corruption exist in ancient tribal societies?

To dream away with all the Viking romantics out there isn't the rational thing to do, mind you. Real states only began to form in 12th century BC with the formation of Kuru Kingdom which had first state level administration in the Indian subcontinent. The Brahmin priesthood and Kshatriya aristocracy, who dominated the arya commoners (now called vaishyas) and the dasa labourers (now called shudras), were designated as separate classes. It's a system that stil works today, but I wouldn't call it less corrupt. Not at all