Your exercises make sense. My son started stuttering while learning to talk around the age of 2. Since I’ve stuttered most of my life, I knew a speech therapist to ask for help. She suggested a very simple remedial technique: get him to practice single syllable words until fluent. Then go to 2 syllable words, and so on until all words flow fluently. After 3 months his speech was completely fluent. I wish I had been taught to speak like this.