One of them is a rescue who was beaten badly as a pup and he took a long time to feel secure and still suffers the emotional scars so for him it was about trying to resource guard me which led to the situation. I personally believe that their past does have very big influence on their behaviour and by understanding how this particular dog has been affected has helped manage the situation in my team. Same with several other working dogs that I have taken on to save them from less than desirable situations. They are different from the pups that I have raised from early on and I use this knowledge in how I train and manage them.
I have spent a lot of time studying my dogs behaviour and training and working with them. I can generally catch a problem long before they are giving off obvious signs and I think this greatly helped with my 2 boys. There is rarely a scuffle these days because I know what they are thinking before they start thinking it lol.
Good luck with yours. Hard to give you specific advise other than with mine I have learn't to read them all like books, I understand what is driving their behaviour, I do a lot of individual training with them and establish a good working bond. They have a good understanding of how far they can push me. I do not play favourites, they are all crate trained, we have a feeding regime where I mix it up who I feed first and they wait their turn patiently and do not interfere with each other. I sub consciously scan their behaviour al the time and have learn't very much to know what they are going to do before they do. I dont have other people involved with them to contend with.
Where I live it gets red hot in summer so I am up early to walk them and also late in the evening. Mine are on a mix of RAW and dry, I can't see why you just cant add a little bit of your kibble to their RAW and over time very slowly increase. We are talking a complete sudden change in diet as affecting their behaviour. I personally don't think that a diet of RAW vs a diet of good quality grain free kibble as long as they are introduced over time to allow their gut bacteria to adjust is going to be a major problem. Not in my own personal experience anyway with the teams of dog I have run over the last 30 years.