Early retirement. Withdrawal. A game

1. We start with C (initial capital) and we want to retire. We want to calculate "w" or how much we can withdraw a month and have a safe future.
2. We are going to hedge the longevity risk by creating a perpetuum mobile, meaning, we are going to keep the principal intact taking inflation into account.
3. Our portfolio will consist of 5% cash, and the rest: 8/13 dividend shares and 5/13 gold.
4. w is going to come exclusively from the dividends. Why? Because we are going to suppose that the inflation will be hedged by the increase in the value of shares and gold.

w=1/12xDIVIDENDx95/100x(8/13xC)x0.7, being DIVIDEND the dividend yield. 0.7 comes from taking 30% taxes into account. The final equation can be rewritten as follows:
w=34103xDIVIDENDxM, being M the number of initial millions.

Practical point of view:
If we happen to have 2.2 million dollars for retirement and we buy shares of solid companies with an average dividend of 3.5%, we can spend 2625 USD a month and feel safe.
From another angle, we think we can live with 4000 USD a month and will receive a pension of 2500 USD a month, how much do we need to retire? w=4000-2500=1500 M=w/(34103x0.035)=1.26 millions.

Some of you might think:
1. Why gold? To hedge the risk of the stock market.
2. Isn't it too much money for such a tiny yield? Inflation is a very powerful enemy, and to overcome it we cannot overspend.