They certainly are inconsistent from my experience. They put my children under "child in need" when my ex dh and I were going through our split. They came in, took a snapshot of life during that period where we were just a couple going through a split and tried to make out that was what life was like for us all the time. 6 months earlier we were on a family holiday to Egypt. Things broke down and we split, I moved out and it took time to settle down.
Ss made a case to try and show our life was like that in general and not because of a split. They didn't listen, wrote down wrong facts and wouldn't change them when they were pulled up on it. The sw wanted me to do a parenting course, I was starting a brand new job which was extremely important because I had previously been working with ex dh and it had taken me a while to find something, so I said I would do a parenting course if it was in the evening so I don't affect my new job. I had the social worker arguing with me on the phone saying I had to do this course, which was on a Wednesday morning, I said I'm not refusing a course, I am refusing to take every Wednesday off for a term when it's a brand new job and this would jeopardise it and it would also leave me short in wages. She even suggested she spoke to my employer 
After I started a complaint procedure, all of a sudden the course wasn't "compulsory," it was "a suggestion " and they couldn't actually force me to do it. When I asked the social worker after why she said I had to do it she lied and said "oh well we never said you had to do it we were just suggesting." So arguing with me down the phone saying I will be doing the course and that they will talk to my employer wasn't making it sound like it was compulsory then?
All at a time when I had just left dh, was starting a new job after 11 years, was moving/buying a house. Ss really did add so much stress and worry at that time and weren't actually doing anything to help at all. I had actually done a parenting course 3 years previously when I was volunteering at the local children's centre. A load of us did it voluntarily because it was interesting. The social worker looked surprised when I told her that in person despite me telling her several times over the phone.
They used the fact I had suffered depression on and off to make it sound like I was an unfit mother. "What are we going to do about her mental health issues " was written on their "plan."
As soon as I complained they shut the case. Apparently my kids weren't a concern anymore after a complaint.
So my experience was awful and they really knocked my confidence as a mother during that time. Years on from that and my kids are thriving and working at greater depth in school. Wasn't such a bad Mum after all..