Do recall that the particular functionality of this quest may include Respawns. In one of the original Naruto: Game of the Year Edition stories, which was begun in 2009, Naruto dies repeatedly, but respawns without issue at a Save Point. It's actually a plot point I think, that he eventually advances the story to the point he can't go back and save the Third Hokage. I could be mixing things up though.
Regardless, if the MC does get dead, then we'll probably get some way of dealing with that.
Also, as someone quoted me earlier and accused me of Fanon, I'll explain why I said that Iwa was Cannon Fodder land, which is related to the databooks and the reality of where each Great Village is situated. Now, of the Five Great Nations, the only one that has a 5 in population is Konoha. This is probably because Konoha is the only Ninja Village that's in a natural population locus. Iwa and Kumo are in the mountains, Suna's in the middle of the desert, and Kiri's a freezing raining wet mess. Konoha, by contrast, is located on the fertile plains, with forests NEARBY but not SURROUNDING IT like all the others and their elements. Konoha can have the most people because it has actual FOOD TO SUPPORT THEM.
Iwa has a 4 and Kumo has 3 in population, and both have 4's in Military. Now, as far as elites go, Kumo has more named ones than Iwa. Iwa has its Kages, Jinchurikki, and Deidara who is a Missing Nin and managed to single handedly ruin the Village's infrastructure using a kinjutsu when he defected. Kumo has its Kages, its Jinchurikki, the Kaku Twins back in the day, the Tools of the Sage, and the bearers of the Black Lightning which is not a kinjutsu.
Basically, Kumo has fewer people, but an equal military, so what military it has is per force going to be stronger than Iwa's. Konoha meanwhile, as of the time of the Databooks I'm basing all this on, was on a peace time footing. It still had more A and S Rank affiliates than any of the other nations though.
Plus, there's always the 'Minato killed an entire army of Iwa Nin single handed' thing from the anime if we're including anime stuff.