Yeah you can achieve any amount of body fat % no matter what the muscle the mass is. Muscle is not metabolic. Metabolism is made up of catoblism or anabolism, you put your body in either of those states through your training diet. I think what you mean is that a higher % of muscle requires more calories for maintenance, so yes 2 people weighing the same if one has more lean body mass they will burn more calories at rest. But you can lose fat to as low % as you like and with a careful diet not lose any muscle.