Well, the same macro economics / historical factors that helped GM, could’ve helped Ford and others.
In particular, other 2/3 of trucks must have come from somewhere.
Ford didn’t own 2 major subsidiaries in Europe.
While GM was buying every company they could get their hands on Forde was too busy with building Fordlândia in the middle of the Brazilian rainforest the best they managed to get is to enter into a partnership with a Russian car company after the Bolsheviks have already gotten into power.
I think GM was much better positioned and it much more decisively went all out on war production Ford made cars and engines during the war GM made everything from bullets to machines guns to tanks and bombers.
