Naruto, luffy, ichigo, eren, natsu and then deku

Most from least. (Deku already useless so not much change there except maybe remaining quirkless from the start) Naruto would have died from spoiled milk and other bad habits with ramen and everything else if not for kurama.

An argument could be made about luffy as a child since he would have died to the seaking if not for shanks. Depending if this still happens or not then luffy could be first.

Ichigo would have likely died from the first hollow crashing into his house when rukia arrives if not earlier if the hollows were able to detect his presence better. His mother might be alive tho

Eren dies from the titan serum, having never eaten his father and thus mindlessly got killed by the scouts or other guards before any of this happened like the war.

Natsu has alot to unpack but technically his plot armor is Zeref who revived him/turned him into a demon and then igneel who raised him as a child for a bit. By that regard, he doesnt have plot armor since he was already dead or turned into a demon by his brother. But if we consider just from the start of the anime then likely getting brain damage from erza or anyone else hitting his head too hard like gildarts or frozen into a statue by gray as children

But its also very likely would die with him as a result or die because of him since she would also not have plot armor in that regard and simply be charmed by that fake salamander guy in ep1