Debre Berhan Corvidae edit

Two species need identification I have photographed these birds for 18 months without being able to identify them. There is an outstanding request for a Somali Crow picture. This images are compressed for ease of upload. Except for corvus 5, I would prefer that you contact me for higher quality images if you want to publish.

There are 3 species here, as well as the Augur buzzard. They are the corvidae I have seen in Debre Berhan. Number 4 is clearly a Pied crow which is included for comparison. All 3 species appear to be the same size, but the pied crow has by far the stoutest bill. In Debre Berhan (2800(+)m.) the Pied crow is the least common, but in Addis Ababa (2400 m.), Pied crows are more common. In Debre Berhan the black corvidae roost in eucalyptus trees, but not colonially.
Numbers one and two are the same species. The all-black corvidae in this area all have brownish heads, and often inflate their throats. In flight this species[1,2] has a wedge shaped tail. At rest tail feathers and primaries are about the same length. The bill of this bird appears to be too weak for it to be Corvus edithae.
Numbers three and five are the same species. In flight this species[3,5] has a short fan shaped tail, often not discernable as being seperate from the wings. (although the photo of it harassing the Augur buzzard appears to shorten the tail even more). The bill of this bird appears too thin and weak for it to be Corvus rhipidurus. At rest the tail feathers and primaries also appear to be about the same length.
Although Sinclair & Ryan describe Corvus crassirostris as Common in this habitat, I have never seen one.
I am considering trying to get photos of the profiles of these birds in flight.
I am now beginning to wonder whether I have misidentified the corvus in image 5. Maybe its the same as 1 & 2 and it has its tail folded under -its hard to see through a camera viewfinder.