'sponsored'
Not a single Iranian was involved, nor did Reagan claim so, although the usual tendency by media until 9/11 was to blame Iran every time somebody cut a fart anywhere outside of the US, only to find otherwise. In fact it was highly suspicious that they didn't blame Iran for 9/11, not even in for a second when it first happened. Which means of course meant the government already had their narrative set, and it did not include Iran. Even the previous attack on the World Trade Center was initially blamed on Iran, until it turned out that that was far from the case.
Another that oddly was not blamed on Iran despite seeming glaringly obvious that it was occurred during Reagan (let's see if you can recall that one). Then again, as with Lebanon, Reagan really couldn't blame them because Reagan was supplying Iran with arms. So if Iran was supplying Hezbollah, and then the US would be responsible because the US was supplying Iran. That would explain why you don't see it in any speeches or demands from Reagan that we should attack Iran in response.
Thousands? Sure, go for it, I got time,,,