Rules of thumb are built for the median household. Complex balance sheets are not median.
The familiar heuristics — a fixed withdrawal rate, an age-based allocation — exist because they are easy to remember, not because they fit every situation.
For households with business interests, concentrated positions, or significant taxable income, the assumptions behind those rules break down quickly.
A plan built on actual cash flows, tax brackets, and liquidity needs will look different from the rule of thumb, and it will hold up better.