I see things differently!
Bhutto had his issues, but in international community he's a secular internationalist. At the same time getting associated with ZuH is considered a stigma...or so I read. I would call Bhutto a lesser evil of the two. The proof to this would be that every year death anniversary of Bhutto is commemorated while Zia's go unnoticed (my personal observation). Somehow I hold ZuH's regime responsible for allowing an aggressively conservative Islamism to take center-stage in Pakistani society. ZuH's policies had long-term consequences for terrorism, but back in those days, they strengthened ZuH's religious clout while ensuring that the Pakistani economy could be kicked into overdrive without disruptions(which is why Pak's GNP grew to be the highest in the world back then). Had Bhutto remained in power for longer then Pakistan might have been more secular today.
Baluch got Saddam's support too, because he assumed Baluch issue would spread into rival Iran too.
I see Pakistan's intervention in Afghanistan as something that helped ZuH to strike freindship with US and western countries, till then he was not recognised by these countries, ergo he saw Soviet attack as an opportunity to turn things in his favor. He was anti-communist and Islamist.