Can't do superchunck but will this help?

I have 8 2'x4' mineral wool panels and am going to use them at a 45 degree angle across the four vertical corners because I don't have enough to cut and stack them to make superchunks. I also have some leftover fiberglass insulation from another room build. So my question is: Would I benefit from loosely filling the cavities created from the mineral wool straddling the corner with regular insulation? Should I not bother? Will it help at the room all? -Michael

Yes, that will do.