For single band superconductors, Anderson's theorem addresses pairing symmetry robustness, however, most modern superconductors feature additional degrees of freedom (orbital, sublattice, or valley) requiring multi-band models and additional symmetry considerations. The concept of superconducting fitness rewrites the linearized gap equation using commutators of the orbitally non-trivial normal-state Hamiltonian with the pairing Hamiltonian. This yields two terms: one quantifying intraband pairing contributions to robustness, another describing detrimental effects. We extend this concept to the time-reversal symmetry-breaking phase transition. While the second-order Ginzburg-Landau term describes the normal-to-superconducting transition, multi-component order parameters can undergo a unitary to non-unitary transition breaking time-reversal symmetry. We apply a similar commutator decomposition to the fourth-order term, enabling prediction of time-reversal symmetry breaking tendency based on normal state and symmetry alone, aiding material research for topological superconductors.