I had problems with Sades & Mooky getting into it with each other and I mean getting into it. It sounded like two male cats fighting outside. Would scare the living daylights out of me when it would happen around 3 in the morning. Anyhoo, they would both get time out in separate rooms with the door closed. It was mostly Sades who was the aggressive one, so he was the one who got the time out most of the time. It ranged from a day, up to 3 days in the room. The last time it happened, he was closed in the room, with my son, for a week. It's been quite a while since I've had to do that.
Now whenever they to go to pass each other, or decide to lay on the bed, couch, table or wherever, I just tell them to be good and when they are, I give them a treat and tell them what good boys they are.

Even though Zach runs from the room when you grab the squirt bottle, I would still run after him and give him a shot. This is what I had to do.

Maybe Zach would be better if he was an only cat, like my rescue Chester is.

Prayers on the way that things will work out with Zach and the rest of your crew.