While i agree with the calculations, i dont think that retail investors have the financial ability nor the willingness to pay 15c-20c for each share they have.
So i think there will be two different offers, one for retail investors (1:1)at a bigger discount, and another one for instos and major shareholders and it will be (5:1 or 6:1)
Collecting $200m from instos will be much easier task than collecting them for retail investors.