I think that the 7th ID was fresh from desert warfare training when they were committed to the Aleutians. They were slated for North Africa and were not equipped for arctic warfare.
On Attu they couldn’t even get up the ridges where the Japanese were entrenched because the draws & valleys were so marshy from snowmelt. They disassembled jeeps & hauled them up by hand, reassembled them & used them to power tow-ropes to drag supplies up to the summits. Incredible ingenuity under fire.
The Army didn’t do everything wrong. They at least had the foresight to recruit Inuits, Trappers & Fishermen who had knowledge of the terrain into “Scout Units”. These guys imparted valuable survival skills to the troops & help them adapt.
Sending the men up there without proper clothing was criminal. They should have rounded up senior generals from the Pentagon and dropped them off up there in their summer uniforms until they figured out the problem.
I went to a military technical school in Texas in 1960. We had mixed classes: five sailors and five airmen per class. The sailors’ received their orders by name from BUPERS; we airmen were given an allotment of five overseas posts, and class ranking decided who went where. Quite a few of our naval brethren ended up in the Aleutians, on the island of Adak. USAF personnel that went from our school to Alaska ended up at Elmendorf AFB. Other USAF schools supplied operators that ended up at St. Lawrence Island or Shemya AFB.