why the call for a Mak'gora? It was pretty clear to me why he did it... it right there in the text:
Saurfang realized that the other allies in the room stood no chance against Malfurion. Some of them already had died in a heartbeat. The old orc also realized that there is no way the other orcs would stop to engage Malfurion, even if it meant their death. A good death is the way of the orcs. The only thing Saurfang could do to prevent this is to step forward and call for a duel, so no other orc was "allowed" to interfere.Malfurion Stormrage stepped through the doorway, eyes fixed on Saurfang. Three of the high overlord’s advisors charged him.
“Stop!” Saurfang shouted.
Malfurion moved, and the metallic claws strapped to his wrists made short work of the two orcs and the blood elf. He stepped forward, over their bodies.
Morka grabbed Saurfang by the shoulder. “Run, High Overlord,” she said. “We will give you time.”
No, they wouldn’t. Not more than a heartbeat. It was time to die with honor. “Take the maps,” he whispered. “Get them to the warchief.”
Morka’s eyes went wide, but Saurfang turned away, roaring, “Malfurion Stormrage! I challenge you to mak’gora!”
The words sounded bizarre to his own ears. What use did a night elf have for an orcish duel to the death? It didn’t matter. Malfurion was here for Saurfang. He would not pursue a bunch of advisors.
Saurfang wanted the other orcs to not throw away their lives, he saved them from themselves basically. Even the lives of some small advisors are important to Saurfang. Of course there is also the objective he was given... the maps. He's a true soldier as well, trying to complete his mission.
That's how I see it, the parts in bold make it pretty clear to me.