From my research of US core market positions I believe I've determined the best 3; being SPTM, MMTM, and DFUS. All 3 contain exposure to large, mid, and small caps unlike VOO, but discard many of the garbage stocks that VTI keeps—so thus have the best of both worlds.
However, trying to decide the best one to have in my portfolio has been a challenge.
Both SPTM & MMTM follow the same underpinning index that contains the S&P 500, Mid-Cap 400, and Small-Cap 600. SPTM then market weight caps all of its holdings, and so does MMTM. But MMTM also scans their momentum, overweighting or underweighting them a bit depending on their score. And momentum has shown a solid factor premium relative to standard market weight capitalization over the longterm.
Unlike the other two, DFUS does not follow a specific index & is technically an actively managed fund (with a list of fundamentals & guidelines to follow) with the largest amount of holdings, and the best rate of return between the three. But due to its actively managed strategy it also holds the chance of significant underperformance if its managing company was to undergo significant changes, which as a large core position could be quite the risk.
If it's of any use, here's the rest of my portfolio which is roughly 20% momentum & 50% value excluding whatever the core may be.
SPMO - 10% (large US mom)
XMMO - 10% (mid US mom)
SCHD - 10% (US val)
LVHI - 10% (Int val)
DFIV - 10% (Int val)
DFEV - 10% (Int val)
AVDV - 5% (small Int val)
AVUV - 5% (small US val)
Thank you for any advice or input you may be able to give!