|There are hundreds of these species. Are you absolutely sure its the poisonous sumac? I would check with the landscaper that planted them. I bet they could ease your mind that they have planted ornamental sumacs. I can't believe that this would be deliberate and they planted ornamentals.
Search these and see if they look like any of your plants:
Rhus aromatica 'Grow Low'
Rhus typhina 'Tiger Eyes' - yellow foliage
Rhus typhina 'Laciniata'
Rhus glabra 'Laciniata'