The idea of using a 4 percent withdrawal rate for comparison is flawed.
The 4 percent withdrawal rate is a safe withdrawal rate for the worst case scenarios in the last 100 years. There are 2-3 years in the last 100 years where you would run out of money in 30 years based on the 4 percent rule. In fact, in all other scenarios, which are much more likely to happen, the person continues to have a significant chunk of their portfolio. Also there’s a very large probability that the portfolio is significantly larger despite a 4 percent withdrawal.
So if you owned your 3.5 million dollar portfolio and withdraw at 4 percent. Not only does it give comparable cash flow, but with a high probability you are likely to have a larger portfolio than you originally had. And most importantly, at death, while your pension goes away, your portfolio can then be inherited by your heirs with a step up in basis.
Then obvious answer is picking the extra 100k from a pure mathematical perspective. It eliminates single company risk, 20 year service risk, and gives you control over your own money while having a significant probability of creating wealth that will out live you, generational wealth, which is the case in most cases in the 4 percent rule.