I think it is pretty obvious that SBM's share price started to...

I think it is pretty obvious that SBM's share price started to tank several months ago when they issued production guidance for the coming years (400k or 500koz/a, can't remember exactly) and it became evident that they had to make an acquisition in order to achieve these production goals. Basically SBM went from 3 to 2 and now below the $2 mark when the proposal to CAH became public.

After consummation of a potential combination the new SBM share price would certainly recover (provided the offer goes through without prolonged infighting). If CAH shareholders wanted to profit from this expected advance as much as possible, they should prefer an all scrip offer since the cash portion would cut them off of any recovery. Should CAH overcome its recent operational issues as planned, the combined company's shares would profit, too, even though to a lesser extent. So while CAH shareholders could deem the offer opportunistic to some extent, they should also consider that fact taht SBM is paying with an at least 30% undervalued currency that is going to be re-valued once the dust has settled.

Bottom line: The combination makes a lot of sense for both companies.