I'd keep it more like PSD, gradually moving towards teaming - for someone whose never driven a truck, that is. There isn't much instruction or supervision to be had if one driver is resting in the sleeper while the other is driving.
You need to trust your trainers judgement but also you need to ask questions too. Is there a way to save yourself time to be able to be more efficient. How do u decide on the routes with gps, mapping with a map is imperative, how do you plan your hours of service around the scheduled time left etc. STOP SECONDS GUESSING your trainer and suck it up and take the training. You guys don't realize you make more money teaming and cover more miles.
That's how its supposed to be done initially... and guess what? Even your dog turd instructor who spent your TnT training period in the sleeper was told that is how its done. He's in the right seat initially supervising your driving until you are capable of handling more of the responsibility on your own. My opinion of your "great" trainer stands. He's was derelict in his responsibility to provide you adequate training.