You can estimate how much cash they expect to invest in the uk.
Take the 48m less spec divi, less capital return, less 10% buyback at some notional price (say 50c) and maybe some tax, and what u have left is what they'll retain to invest into the uk.
They have made a strategic decision, to reinvest proceeds from aust sale into the uk. On that basis we should assume that incremental returns in the uk would be better that what would have been the case if they held aust and turned it around to profit.
Im pretty comfortable that what they are doing now is more sensible and value accretive for shareholders.
TSM Price at posting:
37.5¢ Sentiment: Buy Disclosure: Held