If stored separately, I would consider the seed + passphrase comparable to a 2-of-2 multisig
My impression is that any multisig that requires all of its parts (x-of-x, rather than x-of-y) is inherently riskier because if you lose any key then you’re screwed.
2-of-3 multisig on the other hand would provide equivalent security from attackers with a reduction in personal-error-risk.
My two sats 🤙