The soldiers are competent though. The main difference is that without Hydaelyn's crystalline boost, they just can't exceed mortal limits like the WOL can. Most of the job quests are to the tune of "We're already doing this military operation, but since you're an invincible murder machine, can you help us out?".
You're right, however, that if the WOL just decided to dance a jig while fireballs rained on the field, nothing would change about the outcome of any of the quests or missions. There would just be a lot more NPC casualties than the story claims.