Results of direct N-body simulations including fragmentation for three idealized one-arm initial conditions. In all cases, particles are initially placed on a single branch of the V-shaped distribution and satisfy a common apoapsis, Q = a_col (black dashed lines). Green curves indicate q = R_Sat. Left: setup-1, in which debris particles are initially concentrated in a single localized cluster on the same branch. The blue curve indicates the constant a_eq, or equivalently constant-angular-momentum contour passing through the mean (a, e) point of the initial cluster. The intersection of this curve with the e = 0 axis gives the corresponding equivalent circular radius a_eq = a(1 − e²) in the coplanar limit. Middle: setup-2, in which debris particles are uniformly distributed along the Q = a_col branch. Right: setup-3, in which two localized clusters are initially placed at two distinct locations along the Q = a_col branch.