Hi Pastal,
I think you're a very alert person, it sounds like you will be very good working with Achilles until he goes to his new home. Keep up the good work having him work to earn his dinner, this is a very important lesson for a 4 month old boy who's trying to figure out his place in this home.
I find dogs who are a little tightly wound calm substantially when they understand their place, and when they understand what to do to get what they want. For example, he sits and stays to get his dinner. You can have him earn other things: from now on he has to sit before going out the door, sit before coming out of the crate, sit before playing with a toy. And you will praise praise praise him every time he does that, which will reinforce that you are leader of the pack and he doesn't have to try to be.
Another great thing you can do is in addition to using the house line for safety, you can start to teach him "come" and reward with cookies … make him start to think that you are the source of all things good and he'll hopefully pay less and less attention to the other dogs at all.
Any other lessons / tricks will give him a positive outlet for his energy.