[Winga]

From free transition metal ion, the d-orbitals are degenerate.
In the spherical field, the d-orbitals are also degenerate but in higher energy level.

Is the spherical field meant that the ligands are attaching to metal center equally in position? (but not in octahedral for example)
So, the e- density in each d-orbitals experience the same repulsion?

This approach is not existed, right?

[Demotivator]

The spherical field is purely hypothetical construct. It's a symmetrical field of negative charges around the d orbitals that would raise their energy. When the field "condenses" to point charges as real ligands, then the degeneracy is removed.