It'd probably be more successful, considering the ongoing chaos in Addis Ababa and the fact that Mengistu Haile Mariam's regime had only begun consolidation. You might see the Somalis actually annex the Ogaden and successfully procure international recognition as a fait accompli as the new Ethiopian government is forced to conclude a peace under pressure from the UN while the first step in Mogadishu's dream of a Greater Somali is successfully taken. There's a good chance that the Derg might collapse and this sees Ethiopia balkanize as the Ethiopian Civil War becomes even more extreme with countless factions vying for power - if Ethiopia remains intact, I'm not too sure who might seize power after Mengistu is ousted. Perhaps Tafari Benti or Atnafu Abate?