Oh, the terrible twos!!
I agree that more exercise might help. If it is a dominance thing, maybe special one-on-one time with each dog would help? You could go play tug in the yard with one and then walk the other or something along those lines. Or alternate which dog you take to the mailbox. Even simple things can make them feel special.
What about teaching them separate tricks? One gets roll-over and one gets giving their paw (assuming they don't do this already, but if they do, you could sub in anything you like). Individualized attention AND they are getting some mental stimulation.
I agree that more exercise might help. If it is a dominance thing, maybe special one-on-one time with each dog would help? You could go play tug in the yard with one and then walk the other or something along those lines. Or alternate which dog you take to the mailbox. Even simple things can make them feel special.
What about teaching them separate tricks? One gets roll-over and one gets giving their paw (assuming they don't do this already, but if they do, you could sub in anything you like). Individualized attention AND they are getting some mental stimulation.

) who had become possessive of toys and even bitten his owners badly. She worked on holding his collar and the toy, not pulling, just holding until he gave it up. The first time it took ages but she was prepared to wait and as soon as he gave it up he got lots of praise and a treat.