Thanks for reading and commenting, Robert.
The Taffy thing not going so smoothly. Taffy seems to resent Shadow, and Shadow is afraid of Taffy.
We have noted that the trigger times seem to happen around feeding time, so instead of letting them mingle (which starts fights) we keep them in their rooms while we prep the food.
Then, once feeding is done, we let them wander as they wish. Taffy generally retreats to her fave napping spot, and Shadow wanders around a bit, then retreats to her "safe" space.
We figure slowly does it.