New member needs help pleasd

Are the lakeland and cockerpoo girls by any chance?

Can you describe more about how the fights break out - cockers can have resource guarding tendencies, I'm wondering if any of that is going on?

I can't imagine anti bark collars doing anything other than add more stress to the situation though.

 

Oh dear...3 dogs bundled all of the sudden together and by the sound of it, they are trying to sort out their place and purpose in this group. I doubt it has anything to do with their relation with you but it is purely about themselves. Each of them have different kind of 'needs', not only because of the type of dogs they are but the ages come to it too.
BUT, saying that....it is not impossible that they could not get on in the future...they will need to be trained to be together under same roof. They might never be good friends but they might learn to tolerate each other.
This training could take some time and there is no miracle cures for it.
If you can and have some space to allow each dog have its own area to chill, that would be good start. You will need to read their body language that as soon as there is indication that one of them is starting to react...guide the one that is source of the irritation to its own area and give it a nice chew to tackle and help it to calm down. Or effectively do same with them all. Calmer (and well rested) dogs tolerance levels are better than those that are stressed out..what ever the reason for the stress.
Do not react to their behaviour with a punishment attitude but as 'a guide' to ease out the tension. You are to read and regulate their interaction and adjust accordingly to be ahead of the game and prevent any aggression rising. If have to behave as 'referee', then you are too late with your actions. Hopefully over period of time dogs will learn to recognize what they are allowed to do and what not and you set a routine for your daily life. Use basic commands like 'sit' to help you get by with one dog to go or do something else with other one...and don't forget to praise them either verbally that you are pleased with them behaving and/or with little training treat as you go by.
Of course they will need their physical exercise too to get rid of some that energy that otherwise would be spent ways that could contribute to troubles between the dogs. If they do play together ok outside with more space around them...use that as a bond building exercise. Throw multiple balls them to chase...or maybe a frisbee? As long as all this running around does not create friction it will be great help.
It is hard work for you (your family) and at first very intense training..keep you pockets lined with small training treats ..but it can be doable. Treat is as you would be training pups....but this time around their age is on your side, they've got working brains and they are capable figure things out...as long as they have will to put it in practise.

 

And to add....the American Bully might need extra activity, done separately. Maybe some rope ragging so it can really use its muscles and crastically limit its playing with others. You might need to teach 'be nice'...so it is gentle when being around smaller and lighter dogs. But you will need to be regulator and oversee that interaction all the time. Never leave the dogs to their own devises....things escalate and accident happen very quickly even if there is no aggressive intentions.