As all the cat people on here know, cats are both territorial and pack animals, and one cat usually 'owns' the teritory, and makes sure all the other cats know it.
This one does seem to be over-emphasing his territorial control, which is the weeing and spraing around your house. i wouldn;t worry about his lack of attention, he's hardly feeling neglected or deprived is he!
You need to get a powerful water-pistol, or a squeezy bottle, and not only give him a burst every time you see him, but follow him to his own yard, spraying as you go. This will send the message that you are the 'top cat', and once he receives it, he will back down and stay out of your house and garden, leaving your cats in peace.
Be persistant, and make a deal of it, shoult and run at him while you spray, the object is to intimidate him, so make sure he feels your strength.