I don't know about the CVE, but the earlier Liberty ships were not particularly well constructed (brittle steel that resulted in some of them breaking in half in the middle of the Atlantic under cold conditions).

But for the few that broke in half, several more were sunk by U-Boots. They weren't expected to last many more years after the war (life span of only 5 years) and it didn't matter that much given the short term necessity of the war.