I have 3 dentists that work on separate areas of my teeth.
I have one landscaper that cuts my grass and other landscaper that trims my bushes.
I have 1 plumber for my kitchen repairs and 1 plumber for my bathroom repairs.
Regarding the agreement of exclusivity for the shown properties that protects both parties...that may not be possible as it defeats the meaning of the exclusivity agreement by limiting it to just shown properties...the intent of the agreement is spell out the exclusive relationship and duties between one agent and the agents clients....
My advice is go with the clause that the exclusivity is for a geographic region, that way you can have multiple agents working in multiple locations on your behalf.