Strength vs. Muscular strength is determined by how much force you can exert or how much weight you can lift. Building muscular strength uses heavier weights for fewer repetitions. Muscular endurance refers to the ability of a muscle to sustain repeated contractions against resistance for an extended period of time.
The safest way might be to try to gently pull the dogs away from each other. If not then maybe a bit harder. If they do not have their leashes on then try to distract them with something else. Maybe pull on their collar too.
