Not speaking for anyone, but I think your original question was would you glue these knots in a handle? my answer.....NO,
But I think thing's got side tracked....maybe?
From your pic's I would suggest sticking with the FS - if they are passing your test. As to the others, I think you said a friend gave them to you? so no real loss for you. Your friend may be disappointed, if you inform them of the quality. If you don't then it was still a nice Gesture on their part. Knots are expensive, and the majority come from China - I would suggest the difference is Quality control, and you're going to pay more for that. I think they just don't pack their knots with as much hair as other manufactures (which I think is what is causing the issue JMO). So in my opinion the failed knots are the expensive ones. Other than aesthetics they probably will serve their purpose but I wouldn't sell them.