Cercis canadensis tend to have notoriously weak branch crotches, so I'm not a big fan of them. With proper selection, pruning, and training the frequently narrow crotch angles can be avoided, but I'm not a fan of trees that I have to "baby". That said, I have more than a dozen of them. I've planted two, and the rest were volunteers in the wooded area of my farm. I seriously doubt I will ever buy another one with all the superior possibilities out there.

Both of the ones I planted were planted signally as specimen trees. In landscapes, odd multiples are usually preferred unless you are planting a formal garden (I would go for 1 or 3 over 2 or 4). Finally, the amount of room you have to work should be considered.