Jacob is 2 years old in Feb and is firmly in adolescent cocker boy stage

he guards a lot (from the other dogs not from his humans) and its generally manageable without any major problems.
However, in the last 6 months he has started to growl at the other dogs when he wants attention from his humans, when they want attention from his humans (well, their humans as well!) and when they walk into a room that he is settled in.
(quick background - I live in this house with my housemate and we have 2 packs of dogs, totalling 9. I have 5 - 3 cockers and 2 crosses, housemate has 4 collies all of whom are deaf and two are also blind. 8 of the dogs mix when either one of us are out (1 of mine is fear aggressive so only mixes with a few of the dogs when I am home) and then when both of us are home they separate into 2 packs quite happily. The dogs are rarely left (due to Jasper's needs) but can occasionally be left for up to 4 hours quite happily)
For people who don't know Jacob has had 2 new hips this year, also has a break in one of his knees, has ongoing dislocation issues in his other knee and has spinal pain from disc detoritation. He is on daily metacam and tramadol but still experiences pain and discomfort during the day.
So, I do have to take that slightly into consideration....
Recently his growling has increased and he has started to lunge across the room and bite the other dogs on their face. He isn't told off for growling, but seeing as 4 of the dogs are deaf, they are totally missing this signal and its causing some issues. Dilys, who is blind and deaf 5 year old, gets bitten the most. If you were into pack theory (which I am not) she would be the alpha bitch and will tell the others off as appropriate. She currently isn't reacting to Jacob and stands still for us to remove him from her space but I can see that its not improving and I don't want anything to escalate.
Things I have done so far:
Removed Jacob's crate from the living room as this was a major guarding issue for him
I dont give Jacob any attention when I first come into the living room
Jacob isn't allowed into the living room before the other dogs (he would lay in wait for them by the door and bite them!)
Put more beds into the living space
Verbally telling Jacob and what other dog he is glaring at that they are good and offering shared praise
Verbally asking Jacob to move if I see him stiffen (he stiffens before moving to bite)
Distracting Jacob if I can see him stiffen (either with toys, or me getting up, etc)
All of these have made some difference but he is still doing it. Unfortunately, I just totally over reacted as he bit Dilys and Vixen within seconds of each other and I yelled at him. Totally wrong thing to do I know.
Any other suggestions as to what else I can try? I can't carry treats on me due to Jasper's dementia (long story!) He doesn't do this with every dog, seems to be Vixen (my wimpy bitch), Mabel (blind/deaf collie who is his best mate in play), Jasper (oldie cocker), Della (very nervy and skitty deaf collie) and Dilys (blind/deaf collie). He doesn't do it to Piper (cocker who is generally untrusive), Lassie (deaf collie who again isn't in his face) and Bee (fear aggressive cross breed who would start a fight if he attempted to bite her).