The value in AFNI isn't in millimeters or degrees (or radians) of rotation. So using the "
same" value as other software packages is fairly meaningless. You can approximate, but if you wanted roughly 3mm or 3 degrees, than you want a value of ~ 0.3 for AFNI.
If you don't want to do ANY type of motion correction, then you can remove the "volreg" block from AFNI. That's the step that actually goes through and realigns all of the individual TR images to whatever base you specify (you specified third via -volreg_align_to).