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We theoretically study the magnetization relaxation of Ising spins distributed randomly in a d-dimension homogeneous and Gaussian profile under a soft-core two-body interaction potential 1/[1+(r/Rc)α] (α≥d), where r is the interspin distance and Rc is the soft-core radius. The dynamics starts with all spins polarized in the transverse direction. In the homogeneous case, an analytic expression is derived at the thermodynamic limit, which starts as exp(-kt2) with a constant k and follows a stretched-exponential law at long time with an exponent β=d/α. In between an oscillating behavior is observed with a damping amplitude. For Gaussian samples, the degree of disorder in the system can be controlled by the ratio lρ/Rc, with lρ the mean interspin distance and the magnetization dynamics is investigated numerically. In the limit of lρ/Rc1, a coherent many-body dynamics is recovered for the total magnetization despite the position disorder of spins. In the opposite limit of lρ/Rc1, a similar dynamics as that in the homogeneous case emerges at a later time after a initial fast decay of the magnetization. We obtain a stretched exponent of β≈0.18 for the asymptotic evolution with d=3,α=6, which is different from that in the homogeneous case (β=0.5). © 2022 American Physical Society.