I fully understand and altogether agree with your complaints about working together with other demons. Joint effort is a concept that seems wonderful on paper, yet in practice I find it much easier to work alone. You also face a unique problem in the fact that the other novice tempters around you sound completely incompetent (indeed, you're quite lucky you have me), which is a quality they have bred within each other. Do not let those around you bring you down. Amateurish cooperation is still amateurish. If you work on your patient alone, you will find isolation to be incredibly helpful in all your endeavors. You will also notice that isolation is both the easiest method of work for a demon as well as the central characteristic of a susceptible patient.
I've written you before on keeping your patient out of "community groups" and the like, but all the better if you can keep your patient away from human contact entirely. Obviously, your patient will be forced to encounter others whether he wants to or not, but you should strive to keep these encounters to a minimum. You write that he has many acquaintances that seem to be under the enemy's control (yet another testament to the shortcomings of the other novice tempters). Well, it is your responsibility to keep him away from them. There is no doubt that humans are never fully under the enemy's control, but it is imperative to minimize your patient's interactions with those who are the furthest from our reach. Do your best to surround your patient with people who are under our thumb. Humans naturally become like the humans they spend the most time with, so convince your patient to associate himself with the nastiest people you can find.
If it is unlikely that your patient will find himself attracted to the type of people we would like for him to be with (and this sounds like what you think to be true), then surround him with no one. Let me explain why. When humans are alone, there are only two voices they can listen to: the enemy's and our own. Here, you must be loud. You have no doubt experienced how difficult it can be to get your patient's attention when he is in a social gathering surrounded by many other people. On the other hand, when he is by himself he is desperately searching for someone to listen to. It is imperative that you train your patient to listen to your voice when he is alone. Never cease to whisper in his ear within the stillness of his home. In the quiet, you must breed contempt, lust, greed and the other virtues of Our Father.
Now, there is also the possibility that your patient will use solitude to listen to the voice of the enemy, but this is unlikely. We have the upper hand when your patient is alone in both proximity and effort. The enemy, as you know, dwells not on this earth. He has visited once since The Great Apple (and quite a stir was caused in our ranks upon his arrival), but we succeeded in removing him from earth once again. This land is now ours, so capitalize on the fact that you have the ability to feel much closer to your patient than the enemy. While the enemy claims that he can live inside the humans, we have found no science to back up such a preposterous claim. The concept of "his spirit dwelling within them" is mere propaganda and should be ignored. The humans are ours to dwell in.
Also, you must know that the enemy expects humans to seek him (an outright foolish notion), which could not be more to our advantage. While our enemy waits for the humans to approach him, we must do the opposite. It is our responsibility and privilege to be the initiator and aggressor of all human-demon interaction. If your patient is not actively seeking the enemy, he is practically waiting for you to seek him. Make every effort to do so, and you will find your patient easily won. A human sitting alone twiddling his thumbs is like a sheep standing still in a slaughter house. Take him and make him yours.
Stay lonely, my pupil. Our best work is done alone in the dark.