I think this is overly pessimistic. What remains of the Assadist ideology besides the death cult and fear of torture if you step out of line, is the idea that is a unifying factor that pulls all Syrians together. Once areas of Syria are accepted as permanently lost, the mask covering its reduction to an instrument to keep Assad in place and Iranian interests protected falls away even further (thus I also have my doubts about the Iranian ability to dump the Assads, but I might be proved wrong on that). Assad and Iran have lost ground when they had the legitimacy of sovereignty and the opposition did not, that isn't likely to get better for them if they lower their ambitions to holding what they have, in fact is likely to convince those trapped under the régime that its future is limited.
So rather than the opposition having no strategy, its commitment to resist partition has become easier to keep to with recent advances. There was distrust around the negotiations over Zabadani, but it quickly became obvious that Ahrar al-Sham weren't backing the Iranian proposal. Confusion at first may have led other groups to thinking they were selling out Zabadani, which may have been what led to the early renewal of hostilities. There may be a problem with warlordism among opposition groups, but I don't see evidence for it being the problem here.
But I don't have any doubt that the rate of Iranian/Assadist massacres will increase, for the reasons set out. This is what happens when a people are abandoned in the face of a desperate tyranny, and told that no amount of bombing is a more serious threat than the chimera that the Americans are trying to overthrow Assad.
"The recent intensity of attacks by Assad forces and their backers in Iran’s Revolutionary Guards and Hezbollah in Syria reveals what could be expected to follow soon. We will witness two consecutive phases in the next few months:
1- Ruthless military attacks by IRGC, Syrian army and Hezbollah to cleanse selected areas – deemed strategic and unnegotiable – of the opposition or the Sunnis or both. This will be done under a barrage of soft talks about diplomacy and political solutions, but no serious moves other than the funny Russian initative. All the while, Moscow will keep the diplomatic road opened and oiled with its right hand, and continue giving Assad military hardware with its left hand.
2 – At one point, and after controlling all the strategic areas required, Iran will say that is ready to go as far as convincing Assad to leave Damascus. International calls for “immediate” cease fire will become louder, pressures on relevant parties will intensify and the trilateral alliance will suddenly assume the role of the dove. This will be introduced by this alliance to the world as a genuine love for peace and sincere feelings for the suffering of Syria’s civilians. But in return, the trio will want to institutionalize the status quo, that is to make its areas recognized by the new regime constitutionally the same way the situation in the South of Lebanon is institutionalized as the land of Hezbollah. Tehran is already building the Syrian Hezbollah under the command of the former prisoner in Israel Samir Al Qentar.
The whole Syrian war would have ended with the expansion of Hezbollah and Iran on a larger stretch of territory than what they control already in the south of Lebanon and in addition to keeping the coastal west of Syria. Not bad. Not bad at all. What is the counter-plan of the opposition? None. it is not obvious that the Syrian opposition has a unified parallel plan, either to abort the trilateral partitioning intentions or to wage a meaningful counter-attack.
For example, during the Istanbul talks between the Iranians and Ahrar Al Sham, and while the cease fire around Kafraya and Foua’a was enacted, some opposition groups around the two Shia villages deliberately broke the cease fire to embarrass Ahrar Al Sham.
It is a structural problem in the Syrian opposition that we find warlordism mixed with legitimate political opposition groups. While it is possible to overcome political differences between legitimate opposition groups by reaching a joint political platform, warlordism is not political to start with."