I know it's problematic, but I use ELO rankings of clubs. The only 1 of his last 6 jobs that he took over a team ranked where we are (we are currently 34th in Europe) was PSG who were 38. He spent (when you adjust to inflation within the PL) between 500-600 million in two seasons and left them ranked in the top 10 of Europe.
I am not going to speculate too much, but there would be a reasonable theory to say he has been promised substantial money (akin to PSG) with the intent of doing a similar job.
There will be a legitimate question asked as to where the funding will arrive from.I have my own views on this. There is also a question of how does this fit with having Brands on board and the broader strategy (can he adapt?).
I will be very surprised though, if significant funds were not made available to Ancelotti.
It may sound crazy, but I wouldn't rule out an approach for Koulibaly in January.