Why are d(xy),d(yz) and d(xz) orbitals involved in d³s hybridisation?

Shouldn't d(x²-y²) dxy and dz² orbitals participate? Since this corressponds to the best case overlap?


What factors decide the participating orbitals in hybridisation?


P.S I am well versed with the concepts of CFT and VBT but know little to nothing about other theories lik MOT and Group theory.


