The Edelstein effect enables intrinsic current-induced spin polarization in noncentrosymmetric van der Waals magnets. Here, we compare the Edelstein responses of monolayer Fe3GaTe2 and Fe3GeTe2 using first-principles Wannier-based linear-response calculations. Despite sharing the same noncentrosymmetric D₃ₕ symmetry and selection rules, the two materials show markedly different time-reversal-even and -odd spin accumulations in magnitude, sign, and energy dependence. Strong responses occur mainly near -0.4~eV in Fe3GaTe2 and +0.4~eV in Fe3GeTe2. At the intrinsic Fermi level, atom-resolved analysis shows that Ga-to-Ge substitution reverses the even contribution of the inequivalent Fe3 site for both in-plane magnetization directions and enhances its negative odd contribution, reorganizing the cancellation among atomic sites. Momentum-resolved calculations link the hole-side response of Fe3GaTe2 to a few large Γ-centered Fermi contours, whereas the electron-side response of Fe3GeTe2 involves dense Fe-3d bands with strong interband contributions. The even response arises from incomplete cancellation of opposite-sign intraband Fermi-surface contributions, while the odd response originates from interband coherence between closely spaced states. Magnetization rotation reveals symmetry-constrained angular dependences with higher-order harmonics, especially in the xz plane, while biaxial strain causes substantial amplitude changes and sign reversals. These results show how crystal symmetry, electronic structure, magnetization orientation, and lattice deformation govern the intrinsic Edelstein effect in ce{Fe3XTe2} (X=Ga,Ge).