If the goal is create the best garden you can....
The plants need to placed it the best location to flourish and grow and fulfil their part. They need to be able to do this without impact the others.
If a plant is not growing then you need to question why, is it location, soil, fertilizer, water, to much pruning, to little pruning.
The gardener put the plants to best use. they know that the plants have there place and nature and will aways tend to be who they are, some are more flexible that others........