[Jacek]

These guys didn´t have to be afraid of bombardments.

But the end-users of their antiquated products - I am talking of this particular one - more so.
Afair, the Soviets declined to accept them. They took only a couple of thousands of Shermans, but the Ford built and equipped plants in the USSR chruned somewhat better products in the meantime. Sure: with Liberty engine and Christie chassis.

thus: we have a sort of sandwich: American built tanks from the West, American built tanks in the middle and American built tanks in the East.

I remember having read a book by Antony C. Sutton: "Wall St. and the Rise of Hitler". It said rather bluntly that USAAF, as opposed RAF, deliberately avoided bombing plants owned or partly owned by American capital - and there were many of them: chemical (IG Farben and subsidiaries), electrical (AEG), airplane (Focke-Wolf, among others), tank (Opel, a GM subsidiary and Ford). This could, at least in part, explain, why 1944 was the year of maximum production numbers of armaments in Germany ever - despite horrendous bombardments day and night. And one should not believe that the owners got rid of their production capacity in Germany upon the outbreak of war.
I am aware that these are rather horrendous accusations. They are not mine, though.

However, the sources of the book seemed dependable and the author was Professor of Economics at California State University, Los Angeles, later - a Research Fellow at Stanford University.