I am not sure about the three securities mentioned alone. I personally like to be more diversified and tamp down on the volatility, even at the cost of giving up some return.
However, the tilt towards allocating a lion's share of your capital to passive strategies makes a TON of sense, and this is coming from someone who for a long time was firmly in the stock picking camp, and has still a majority of capital allocated to individual stocks.
It just offers a great effort to reward ratio, which is very difficult to beat except for those with the time, enthusiasm, skill and actual results to justify being more active.