Mane in Lego to the Saudi Pro league and Kane to be recruited as a substitute is the scenario that is being carried out by Bayern Munchen so far, the realization of a fast move gives Kane plenty of time to adapt.
The last news that i have heard about a possible transfer of Sadio Mane to al-nassr was that Bayern would let Mane go for a transfer fee of around 30 Million €. If those numbers are true, then this obviously is not even a third of the amount that Tottenham is asking for Kane probably a fourth with bonuses included. I am pretty sure that there will be official confirmation about a transfer of Mane to Saudi Arabia pretty soon but i doubt that this will have any influence on the situation with Kane.