I managed to give the club a financial advantage over others by giving it an income of 1 billion per season, always renewed on fixed value, but it doesn't matter much because most of that 1 billion will be eaten by dividends for some reason. Moreover, even with this advantage the club will still not sign the Mbappe's and Haaland's even with newly created perfect chairman and general manager. But, it's still a big improvement compared to without the income, sometimes even winning the EPL within 5 seasons when lucky, but hardly dominating.
If I raise the income to 2 billion, I found out that the club's finance will overflow. It seems the memory is capped at 2.5 billion and once you reach that it'll overflow to negative 2.5 billion. So unless I can find out how to stop dividend payments.
Another way is if they increase the memory allocated for club's finance, I hope they would. In another thread I also asked about stadium capacity above 325.000. I know these aren't realistic, but for me part of the fun of FM is to try this kind of unrealistic scenarios and see what happens.