Deeper substrates help hold them in place till root development is sufficient to hold them in place.
Not too long ago I placed a couple large sword plant's in my tank and flow from spray bar kept wanting to dislodge them.(current hitting the broad leaves)
Rinsed some more safe-t-sorb I am using for a cap over dirt and placed the extra around the base of the plant's and no more uprooting.
Need shoulder's of base of the plant above the substrate IME
Thought four inches of dirt would hold them in place but was not to be.
These were XXL plant's.