I agree with Dixieland Dancer
You need to give your animals plenty time. And you also have breeds that especially need this.
I found Chilli was a good way to help in training my Holly not to chew, I would mix it in Petroleum jelly and stick it to my reticulation (she had a particular fancy for this), but the true solution was to keep her routine regular with plenty of excercise and alternative chewing exercise. I kept plenty of bones on standby. Excerise is the key, take them out before you go to work and let them burn some fuel, it'll be good for you too! Can you arrange for a dog walker or someone to give them some play time if you really are stuck?
Given that they are strays you haven't had the chance to train them since the were young but they are still at the perfect age to train them, you'll need to be patient and persistant. They're going through some tough times with not being able to be with you, cos your the top dog.
Good Luck with it all. I'm sure you'll get through it. Give them plenty of love and time and all will be well.