If one analyses their strategy its empty: their fame is made in beating disorganized France.
Their so called innovation, the BlitzKrieg was effective, only as long as they had technological superiority: Poland with a 19th century army(1939), a disorganized France (1940) and early stages in Russian Campain (1941-1942) with a disorganized and poorly armed Red Army .
In contrast, the Red Army's retreat, resistance and counter attack was really amazing.
It showed how the Red Army high command learned fast and applied it directly into the battlefield;
The German High command lacked this capacity, they were not able to adjust to the situation.
Until late 1944 they were dreaming of a kind of blitzkrieg to annihilate the red army in south russia.
Gara Man,
Bareeeytuma might be a band of raiders, but they occupied the land and
still live there (from Harerge Highands upto to Khamise in Wallo)

where as the forces of Imam probably raped every female they found and left for good.
Aliyyi,
Muslim Sultanates were strong political structures! at the time the Adal kingdom had a life streching on 5 centuries.
There were strong Muslim Sultanates in Showa highlands!
The Imam sentenced them to death by directly aiming to annihilate the abyssinian kingdom.
And abyssinans annihilated those kingdoms!!
Lets us see a possible scenario if Imam didnt do his destructive war:
Bareeytuma would have been incorporated in the Adal kingdom will strengthen the muslim force and crush abyssinans in the eastern highlands and wallo.
Northern Borana would have been incorporated to the showan sultanate and abyssinan kingdom will face emboldened Tulama Maccaa in its heartland Gonder and Gojjam.
These two moieties led by such a strong ideology such as Islamism would have crushed the abyssinian kingdom and turn it into a muslim one.
B.