The four percent SWR is based on a portfolio of paper assets. It is not applicable to rental values or income. If you are doing things correctly, the yield of your rental property should be more that four percent of the value. Dividends from a stock portfolio are usually much less than that, and you sell shares to get your four percent withdrawal. There is no decumulation of a real estate asset unless you sell the property.
One approach that is reasonable is to make a conservative estimate of net rental income. Subtract that number, along with the expected income from pensions and Social Security to get the income that must be generated from your paper assets. That income should include the tax on all your income, no matter how the income is generated. For example, assume you need $100,000 in gross income in retirement. You get $20,000 in net rental income using conservative assumptions and $20,000 in Social Security. Your portfolio will need to generate $60,000 to make up the difference. Your paper asset portfolio would need to be $1,500,000 to get the $60,000 using a four percent withdrawal rate.