What the design buys
The three benefits are related but distinct, and each of them is something a single-account design cannot recover later.
- Faithful replication: a leader's long and a different leader's short both exist.
- Attribution: scoring and replacement need per-leader PnL, and only isolation produces it.
- Containment: a liquidation in one sleeve consumes that sleeve's collateral, not the whole book's.
- Clean replacement: removing a leader closes one sleeve and leaves the other nine alone.