We highly recommend anyone interested in "Sudanic" Africa or the history of the Sayfawa dynasty to take a look at LaVerle Bennette Berry's dissertation on the Gondarine period in Ethiopian history. Although The Solomonic Monarchy at Gonder, 1630-1755: An Institutional Analysis of Kingship in the Christian Kingdom of Ethiopia is focused on a very specific period in the history of the Solomonic monarchs before the the Zemene Mesafint, Berry argues in favor of placing the Ethiopian kingdom in its African context and sees strong parallels with Borno's ruling dynasty. Of course, Berry's understanding of Borno political and economic history is through the lens of Cohen, particularly on Borno feudalism, but there are some interesting parallels between the two dynasties which might suggest some utility of contextualizing both as "Sudanic" states of a particular type.
We would also add the Keira sultans of Darfur, the Istambulawa of Agadez, the Askiyas of Songhai, the Funj, probably Wadai, and maybe Bagirmi to our list as examples of other "Sudanic" states which, despite their religious differences (Islamic, Christian, or "pagan"), hint at deeper commonalities, influences, and particular "African" responses to universalistic religions, long-distance trade linked to the Mediterranean and Eurasia, warrior states, and centralizing authority. Naturally, one can find vast differences among the various polities and kingdoms that developed across the region, but some of their commonalities and perhaps similar relationships to the outside world can be illustrative of dynamic African polities. Nonetheless, the Sayfawa and Solomonic dynasties, both lasting several centuries, offer a better possible comparative approach despite the much richer corpus of sources for Ethiopia.
In addition to their longevity, they were regional powers, used vertical rather than horizontal links, supported a universalist faith, claimed illustrious ancestry through their respective religions as a political "fact," were built on, at least somewhat, on war and raids, and relied on a system of "fiefs" with delegated authority for administering the provinces and countryside. To a certain extent, one can see periods of Bornoan decline when the mai was less active, something akin to the problem of Ethiopian emperors who did not campaign and thereby lost one of the major sources of their authority: providing booty, captives, and honor to soldiers who served them. But the parallels between the two dynasties and their respective declines may be due to divergent causes by the 18th century.
Certainly the rise of al-Kanemi in the 19th century was due to external pressure on Borno from the west while the reduction of the Ethiopian emperor to figurehead by the time of Iyasu II was, according to Berry, a product of several decades of internecine strife among the nobility, clerics, and factional strife that saw the rise of the ras and assassinations or depositions. Unfortunately, we don't have enough sources on the Sayfawa dynasty to track all the coups, assassinations, and depositions to the same degree, yet Borno's eventual reliance on enslaved officials may have been a mitigating factor. Nor does one find evidence for the type of internecine theological disputes and factions in Borno that characterized Gondarine Ethiopia, unless one wants to try to argue that Sufism under Umar b. Idris represented a threat of sorts or later conflicts between the royal administration and non-aligned ulama was comparable. Thus, one should not overstress the commonalities or deny the obvious differences in environment, ethnicity, religion, and the vast corpus of chronicles that have survived in Ethiopia versus the smaller corpus from Borno.