Askia' army lost the battle because the enemy had the advantage of firearms. How exactly they would have been able to hold off the Moroccans without arquebuses even if miraculously they somehow managed to repel the invaders? They do need experienced arquebusiers terribly in order to survive in this speculative scenario / with guns they would have been masters of this part of the continent.
It is worth noting that this may be incorrect on four accounts:
1) In the Tariq Al Sudan itself, it states that the Songhai did not lose due to firearms, but because they did not believe the Saadi Sultanate actually intended a full-scale invasion, and the Songhai threw together an army with poor leadership.
2) Whereas it took them awhile to win a major battle agains the Saadi, they did did very well later with guerilla warfare.
3) The Dendi empire, the survival of the Songhai, did win a major battle agains the Saadi under Askia Nuh.
4) The Saadi suffered miserably. In the Tariq, is says that of the 23,000 soldiers sent to Songhai overall, not 500 made it back to Marrakesh.
So they may have done a bit better than we think against those primative firearms. Some of it was just getting caught flat-footed.
