If I had to rewrite the plot and put myself in that era and have things my way, I would have merged the two along with other Isaac Houses into one powerful force. Not that many years before 1868, the Eidagale Sultanate was said to have possessed the most cavalry army in the entire region.
After merging all Isaac's various groups, Sultanates, leaders-----next I would have either invited or subdued the Ogaden; remember many Ogadens were under Eidagale already and worked with them closely. After that I would have marched west to Gabiley to request the Sacad Muse to subdue or assimilate all Jarso, Akisho, Gurgura and Oromo tribes as far as Dire Dawa (then it didn't exist).
After that I would have assembled my force of all these groups and marched towards central Abyssinia where various Lords and Warlords of the Highlanders were battling out. All I needed was to defeat one or two of them and focus on entering Wollo from southeast and eastern front.
Once I have arrived in Makdala in Wollo, I know there would have been little resistance since during this era, the British forces destroyed most of Abyssinia's military defense and there was great turmoil. It was the year Emperor Tewodros II committed suicide after the British defeated his army and almost captured him.
Once I had arrived in Makdala, I would have changed my qabil lineage from that of HY and Garhajis to HJ
You see by then I would have met Abyssinia's elders, religious figures and other key-players. By changing my Isaac ancestry of Garhajis to Isaac HJ, I would have argued that I have every right to declare myself Emperor of Abyssinia since my ancestral mother, the mother of Isaac's HJ branch was Habesha and hence Solomonic blood
I would have argued that myself and the son of Tigray stood equal distance when it comes to the throne. If son of Tigray can claim the right to rule through his maternal lineage, so I can.
Because I would have had more powerful army than Tekle Giyorgis II (Wagshum Gobeze) of Lasta and Wag (Wollo), there would have been great chance that I would be the first Isaac Emperor of Abyssinia.
When Tekle succeeded Tewodros II, he ruled for mere 3 years. He claimed to the throne by claiming he was a descendant of the Agaw Zagwe dynasty that was unseated in the late 12th century. His strong argument however was that he had Solomonic maternal side just like any son of Habar Habashuud (HJ).
After his death, the throne was claimed by Yohannes IV of Tigray/Enderta. His argument to the throne was like the previous Emperor; maternal. Yohannes himself had small army but respectful army under Ras Alula Engida but were already stretched to their limits. They were fighting Ismail Basha of Egypt, Sudan's Mahdis, Kebessa rebellion, Ottomans were occupying parts of Eritrea, etc.
I would have teamed up with Mohammad Ali of Wollo (Ras Mikael) and other Oromo warriors including Gobena Dacche and even the Mahdis of Sudan who were operating a wide operation from north Tigray to western Wellega.
I am saying Isaac brothers lost golden opportunity in that era while they were too busy raiding Dhulbahante and Ogaden camels, they knew little of the world just beyond the hills of Gabiley.
That is probably how I would have conducted things.
Ras Hawdian-----------hhhmm Emperor Hawdian I
Too much emotions in this nicca.
