DWAQ
Invesco DWA NASDAQ Momentum ETF
stock NASDAQ

You mentioned 5-10% SCV or momentum ETFs. I believe the oldest momentum ETF is DWAQ. It was active from 2003-2020, ending in 2020 after underperforming S&P 500 during that 18-year period. Next oldest I am aware of is MTUM, which is available from 2013 to present. Over this 13 year period returns were 14.4%/year for MTUM vs 14.2% for S&P 500. Throughout this nearly 25 year period, there was no notable advantage of the listed momentum ETFs over S&P 500. Small cap value didn't fair better. Over the listed nearly 25 year period. SCV had a 10.5%/year vs 11.3%/year for S&P 500, using the SCV index on Portfolio Visualizer.
My point is it's not that simple that if you invest 5-10% in SCV or momentum ETFs, you will get superior returns. If it was, everyone would do this. Now that the historical SCV advantage in previous decades is common knowledge, included a related Nobel prize, it's debatable rather than advantage still exists. Organizations investing billions tend to take advantage of this type of public knowledge and related opportunities, until they are no longer possible.
If the SCV or momentum ETF advantage still exists, how much benefit do you expect to get by allocating 5-10% or portfolio and paying higher fees/ER to whichever ETF is choosing which stocks qualify as SCV/momentum for you? Is that benefit worth the likely increased portfolio advantage, increased personal stress when monitoring, and increased risk of making bad decisions if you see it underperform over short term? Not everyone would answer yes, particularly in the Boglehead sub, as Bogle preached almost the exact opposite of this approach.

You mentioned 5-10% SCV or momentum ETFs. I believe the oldest momentum ETF is DWAQ. It was active from 2003-2020, ending in 2020 after underperforming S&P 500 during that 18-year period. Next oldest I am aware of is MTUM, which is available from 2013 to present. Over this 13 year period returns were 14.4%/year for MTUM vs 14.2% for S&P 500. Throughout this nearly 25 year period, there was no notable advantage of the listed momentum ETFs over S&P 500. Small cap value didn't fair better. Over the listed nearly 25 year period. SCV had a 10.5%/year vs 11.3%/year for S&P 500, using the SCV index on Portfolio Visualizer.
My point is it's not that simple that if you invest 5-10% in SCV or momentum ETFs, you will get superior returns. If it was, everyone would do this. Now that the historical SCV advantage in previous decades is common knowledge, included a related Nobel prize, it's debatable rather than advantage still exists. Organizations investing billions tend to take advantage of this type of public knowledge and related opportunities, until they are no longer possible.
If the SCV or momentum ETF advantage still exists, how much benefit do you expect to get by allocating 5-10% or portfolio and paying higher fees/ER to whichever ETF is choosing which stocks qualify as SCV/momentum for you? Is that benefit worth the likely increased portfolio advantage, increased personal stress when monitoring, and increased risk of making bad decisions if you see it underperform over short term? Not everyone would answer yes, particularly in the Boglehead sub, as Bogle preached almost the exact opposite of this approach.