The elements of lawfulness under Article 90 refer to the authorization - that is, the legal authority.
I don’t care who actually GIVES the order. What matters for Article 90 purposes is who or what AUTHORIZES the person to give the order. If the President’s approval is needed in order for 30,000 extra troops to be sent into combat operations, then the authority to send those individual soldiers comes from the President.
Without the President’s action, no authority to send those troops exists for that brigade commander.
We can see that clearly in the case of Iran. If the President doesn’t give authority/approval to send combat troops to Iran, the brigade commanders’ authority to deploy those troops doesn’t exist - and any such orders they gave would not be lawful because they wouldn’t meet criteria ii under lawfulness for Article 90.
If I’m remembering correctly, Obama did give an order for 30,000 additional troops. He signed it after Obama asked if there were any objections, the military commanders said they approved, and Joe Biden simply asked if that was Obama’s final decision (after Biden had been arguing against a surge all along).
Your’re not listening or you’re not reading anything I’ve provided. And you’re taking the authorization theory to an extreme. Take it further to the extreme and then Congress is the only authority. Without Congress’s action, no authority exists for the President.
Brigade commanders cannot issue deployment orders. The SECDEF must do that.