During WWII, several companies including CASE and Ontario were contracted to make the Ka-bar knife since the Kabar company could not keep up. When your standing military force is in the millions, a small NY company can't be expected to keep up. So other companies were given the spec for the knives to keep up supply to meet the demand of the war.
That being said. I have used Case, Camillus, and Ontario knives. All of them were either sold, returned, or given away. On the other hand I have two genuine Kabar knives with about a dozen more made by Kabar the company. I have only had a few Kabars fall short of the expectation I have had for them and those were the ones I expected such as the Warthog folder.