Completely occupying the Eastern Plaguelands was impossible. Even setting aside how many troops it would take, what use would Quel'Thalas have for a land riddled with plague, even if it occupied the entire region?
By now, the entire Eastern Plaguelands had become a paradise for the undead, with Stratholme and Naxxramas constantly watching for an opening. Faced with these two formidable enemies, even if Patrick captured them, the casualties would be unacceptable.
Patrick's main objectives were to allow Blood Elf troops to enter the Eastern Plaguelands freely and to soften the hostility of the Lordaeron Remnants in the Scarlet Crusade.
Moreover, Patrick had chosen to attack Stratholme from the sea mainly to avoid the brunt of the undead's forces while also surveying the sea route from Quel'Thalas to Stratholme, preparing for a direct connection between them in the future.
Once the Scarlet Crusade occupied Stratholme, its supplies would remain inadequate in the face of that deeply contaminated land. Wouldn't the harbor outside still be firmly in Quel'Thalas's grasp? In fact, the entire port might even fall under the Blood Elves' effective control.
"Going by Quel'Thalas's population alone, we can't handle the defense of vast territories. Although we've taken in some Highborne, ogres, and treants, territorial expansion would still put us under enormous strain. Once we occupy a large stretch of the Eastern Plaguelands, we'll have to guard against attacks by the Scourge. As the fighting drags on, we'll have no choice but to commit more manpower to strengthen our defenses. That would practically mire the entire kingdom in the Eastern Plaguelands."
Alleria kept her hands busy, peeling grapes for Patrick. "What about continuing to take in other races to fight for us?"
"That wouldn't work well either. We can't guarantee that other groups under our protection won't harbor divided loyalties.