The reason why religious minorities have been the most politically secular people in their respective countries in the Mideast is because sectarianism only works against them (even assuming they bought into that). So to say Hafez Al Assad believed it was a good idea to build support by being as sectarian as Abdulaziz ibn Saud or Khomeini is far fetched. Alawites were 10% of Syrians, and don't exist much outside Syria. Assad wasn't particularly adept or strong, so shooting himself in the foot would have only made things worse for him. He wouldn't have lasted a few years if he'd been that unwise.

Saddam played to sunni themes as well,

Err not really, and we never experienced such a thing. He played to Iraqi nationalist themes and historical themes. The propaganda was so stuck up the ass of ancient/medieval Iraq and nationalism, you'd think Iraqis were a bunch of post-modern atheists (despite always having been a very conservative Muslim country).

Is the "Sunni theme" you're referring to the Muslim theme of putting the Takbir on the flag to rally support among a very and increasingly conservative Muslim country who for a long time many people were upset with his secularism (especially during the ongoing Islamic revival period, where just every Muslim country was making concessions or even having Islamic revolution)? It comes as a surprise to many people, because they saw a picture of a picture of a couple privileged women in Kabul in the 70s dressing up like Western women (a far cry from the general society in Afghanistan, both then and now), but secularism is to many people in the Greater Mideast what Communism was to Cold War America. It's scary and it's blasphemous.

To give an idea of how much Saddam cared for "Sunni themes", he, much to the anger of Muslims, was the guy who supported "infidel" Hindus against Muslims, to give you an idea of how much he cares about religious themes compared to standard political and economic relations and agreements. He worked with "infidels", Communists, and others across the world opposed to Islamism, while himself smashing Islamists and jihadists.

And I don't know what all those self-hating Shi'a Arabs and self-hating non-Arabs were doing joining the Iraqi Baath party in throngs. Saddam was not only a nationalist, but the most nationalistic politician Iraq (or arguably any Arab nation) has seen.

One thing he was really good at was dealing with the tribalism, Iraq's #1 issue. Unlike most countries, in Iraq, nearly all the Arabs and Kurds belong to tribes, and God forbid anyone has more authority than the sheikhs. Tribalism is easily one of Iraq's greatest issues. This is why when he was very rapidly developing Iraq, bringing services, institutions, and government into places that really didn't have it, lots of tribal structures were upset. But he knew how to appeal to them, work with them, even leverage them against each other in situations of insurgency and terrorism. One of the biggest reasons why Iraq is in anarchy and chaos today is that modern government and administration has been replaced by the independent-minded tribal structures.