Hi
I've known lots of golden/red cockers and only one with rage (and I'm unusual for knowing a rage dog). Any dog not socialised properly can be difficult with children - in the same way that children not socialised properly with dogs can make a dog's life hell.
Rage, in my view and from my limited personal experience of one dog, is a mental problem, akin to epilepsy, and has nothing to do with upbringing, socialisation, etc. Many people who have an aggressive cocker blame it, completely wrongly, on rage. Rage and aggression are not the same at all. Aggression in cockers is usually due to poor upbringing, lack of socialisation, and people who buy them thinking they are lap dogs, people who buy them because they are cute but don't train, etc., etc..
The vast majority of cockers are wonderful. One of my rescues, Pip, has been treated very badly in his life - but still retains his love and trust for humans, and is 100% safe around any child.