In my non-expert opinion, if I knew I wanted to be, say, 75% stocks and 25% bonds, and if I had a Roth IRA and a work 401K, I'd add the total of both accounts together and hold the 25% of that total in bonds in just the 401K.
My reasoning is, if I'm going to get lucky and hit a home run with stocks somehow, I want as much of that potential growth in the Roth IRA so I don't have to pay any taxes on it. I'm not likely to hit it big in returns on bonds.
For example, if my 401K was worth $200,000, and my Roth IRA was worth $100,000, I'd want to own $75K in bonds and $225,000 in stocks. So I'd make sure my 401K held all of the $75k of bonds, and the remainder ($125k) in stocks. My Roth would be all $100,000 in stocks.
An HSA focused on being mostly a retirement vehicle I'd include in the total as a place to lean more toward stocks since, again, if I get lucky and somehow buy the next Netflix in there, I want to get that win completely tax-free.