A Forbes columnist last week warned that asset allocation is falling on hard times. Rob Isbitts, founder and chief investment officer of Sungarden Investment Research, writes that “if you started investing in a typical asset allocation strategy any time since mid-2012, your returns have been progressively worse.” Using a set of BlackRock asset allocation ETFs as evidence, he says the standard asset allocation strategy has “lost its mojo.”

This sounds rather ominous. After all, if asset allocation’s efficacy is fading, successful portfolio design faces serious challenges. “And based on the precarious positions of the stock and bond markets today, I would not want to be in a position of counting on a return to glory any time soon,” he advises.

Perhaps, but unpacking this cautionary analysis leaves room for debate about the prospects for asset allocation in the years ahead. Yes, it’s fair game to take a cautious view these days on expected returns for risky assets. But that caveat should be separated from evaluating the value of asset allocation.

Let’s start by recognizing that minds will differ on the wisdom of using Blackrock’s iShares asset allocation funds as a benchmark for multi-asset class risk and return profiles. Consider the iShares Core Moderate Allocation (AOM), for instance. While it’s true that the ETF’s performance over the last three years has been moderate, perhaps even lackluster, it’s not obvious that this fund (or its counterparts at iShares) is the last word on what might be termed conventional asset allocation.

As one example, let’s compare AOM to Vanguard Star Fund (VGSTX), a simple but broad-minded mix of other Vanguard funds that offers a reasonable alternative as an asset allocation benchmark. Over the past three years, the two funds have diverged, with VGSTX posting conspicuously stronger results through yesterday’s close (August 14).