The structure and relative stability of higher-order He3,4I2 clusters are investigated by carrying out full-dimensional quantum calculations within the multiconfiguration time-dependent Hartree framework. The full interaction between the I-2 molecule and the He atoms is based on analytical three-body ab initio He-I-2 potentials obtained from high level ab initio calculations plus the He-He interaction. The low-lying minima on the potential surfaces are found to be very close in energy with the He atoms in a ring encircling the dopant for the global minimum structure, while for the local minima one or two of the He atoms prefer the linear arrangements along the I-2-axis. Such classical description on the basis of the potential energy landscape is corrected by including anharmoriic quantum effects, present in highly floppy systems, by carrying out Pull dimensional quantum calculation. The potential energy operator was constructed by natural, fits, while a mode combination scheme was employed to optimize the computational cost of the improved relaxation calculations The obtained results predict the relative stability of the He3,4I2 isomers at zero temperature and provide benchmark data on binding energies and structural properties of these Van der Waals systems. The,(2,1) and (2,2), involving two He atoms in the T-shape-and one or - two He atoms in the linear configurations, respectively, are found to be the most stable isomers; although extremely close in energy with the (3,0) and (4,0) Azines as predicted by classical optimizations. Comparison with experimental data on similar systems at low temperatures is also discussed This analysis indicates once more the importance of quantum delocalization and The need of accurate quantum-mechanical treatments, to characterize such doped helium nanosystems.