Not disputing anything you said. All true. The problem was Stevens requested more security at the consulate and was denied. That is the state department. The contractors got involved rescuing the personnel at the consulate.
Well not exactly because it wasn't exactly Stevens doing the requesting and it wasn't exactly Hillary Clinton handling the requests. So while Politifact rates that "requests were made" as true, it explained that many of the requests were made before Stevens was ambassador some even before Hillary was secretary of state.
Left out of the Trey Gowdy hearings were these facts.
The facts of what happened and why were clearly established by the Accountability Review Board:
Ambassador Chris Stevens was responsible for the decision to travel to Benghazi. In-country travel is solely at the discretion of the ambassador, and he did not need to seek Department of State approval.
He traveled to Benghazi knowing full well that his physical and personnel security concerns had not been adequately addressed by the State Department's Bureau of Diplomatic Security. Despite the security concerns, he traveled nonetheless due to personnel rotation in Benghazi and to re-establish contacts in Benghazi.
He left Benghazi on November 17, 2011, and returned as ambassador to Libya on September 10, 2012. In that intervening time, and in the six months prior to September 11, there had been 20 security incidents. Despite a CIA presence in Benghazi, Stevens was unaware of the evolution of the militias that subsequently killed him and his colleagues.