The latter from the IUCN reintroduction criteria perspectives' is currently a no go area for black rhino. I rather would take that risk with the white rhino.
I do hope the EAZA will intervene on this one as the PL and Howletts' rhinos are part and parcel of the EEP (and not owned by DA or Aspinall Parks) and this really is the illest-advised project for now DA has come up with.
First and foremost both Somalia (I am not talking about either Puntland or Northern Somaliland) and Sudan require first and foremost constructive investment in their current protected area system and species conservation programmes on the ground for native species already under threat.
I mean this is the Horn of Africa with many locally endemic and critically endangered species and one of the unsafest territories in Africa. I include for reference purposes here also areas like the Near East and Central Asia with Afghanistan, Syria and Iraq as some of the worst and not dissimilar examples of civil strife, areas unsafe for all local nationals and ridden with inter militias' strife and warfare and the local civil population always the No. 1 victims.