>>2416808>>2416812i'm not so sure if this in blender (it should be) but in pmxeditor there's an option where you can select a couple of vertex, copy and "mix" their coordinates and then store temporally in the editor's memory a new one, which you can use to re-positionate another selected object, be it the same group or vertex you used previously or another. it's in the pmdview window: in EDIT>Selected Object>vector copy of the mid-range position, this is the one that copies and mixes them, the ones that apply the fused coordinates are the other two options below.
.try to do that with the all the vertex that i marked and then use that new coordinate on the one you want to move
