No two will have used the same number of d-orbitals. However,
To apply the Valence Bond Theory, determine 1. the number of bonded pairs and 2. number of non-bonded pairs. Sum of BPrs + NBPrs => Number of Hybrids needed from valence structure. (Remember, Valence structure will be the highest principle quantum number of the electron configuration.)
Bonded Pairs (BPrs) = Number of elements attached to central element (we'll call these 'substrates'). Simply look at subscript after substrate element => number of bonded pairs.
Non-Bonded Pairs (NBPrs) = (Valence Number - Substrate Number) / 2
=> Valence Number is total number of valence electrons. If structure is cation, also subtract 1
=> Substrate Number is total electrons in valence of substrates when bonded. This will be '8' for all non-metals except hydrogen which will be '2'.
Number of Hybrids needed (all single bonds) = BPrs + NBPrs
Apply same sequence to remaining formulas of interest.