This paper presents three independent and mutually reinforcing theoretical derivations of the Higgs boson mass within the SU(4) vacuum polarisation framework. Each derivation is physically motivated, mathematically explicit, and avoids circular reasoning. The first derivation is the Coulomb-Yukawa vacuum polarization absorbed energy redistribution method, in which the scalar mass arises from the curvature of an effective potential generated by fluctuations in the electromagnetic partition between long-range Coulomb and short-range Yukawa channels. The second derivation is a two-channel SU(4) binding analysis in which the Higgs is the lowest scalar eigenmode of a neutral/charged weak-boson bilinear system. The third derivation is an SU(2) spectral method based on representation weights of the compressed SU(2) vacuum. All three approaches converge on 125-126 GeV. The agreement among these methods strongly supports the interpretation of the Higgs boson as a composite excitation of the SU(2) vacuum. (This paper has been fully proof-read and corrected by Copilot AI to make it more readable than the draft.)