Both of you are right in your assertions. Identities related to Race / Occupation / Ethnicity / Linguistics overlap so much that its impossible to say anything either way. My understanding was that Jat (pronounced Jaat, with a strong 'T') is nothing but the Hindi word for caste, which is Jaat (pronounced with a soft 'T'). The theory being that when Indo Scythians settled in the Punjab plains and took on the role of agriculturists, they realised that they didn't fit into the Indo Aryan caste system. Remember that Indo Aryans were nomads before settling in India and did not have an agricultural caste. Large land owners were powerful people and it was not acceptable to them that they be considered outcastes. So they probably used the word Jaat to insist that they are people with a caste. This may be all hogwash, and maybe the word Jutt originates elsewhere.
What would you say Punjabi is? A regional identity? A race? A linguistic group? An ethnic group? All of it?
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