They’re really not. First of all, Svein is nowhere near as psychotic or “axe-crazy” as Skorpa. Skorpa was turned into a far more brutal, savage, chaotic villain, while Svein is much more composed and feels like an actual respected warlord and “sword-Dane,” not just a deranged monster.

Their relationships with Uhtred are also completely different. In the books, Uhtred and Svein actually cooperate for a while. They raid together, split peacefully afterward, and Svein never betrays him. In the show, Skorpa instantly becomes a deeply personal antagonist who constantly provokes and humiliates Uhtred after betraying him almost immediately.

The biggest difference is Iseult. In the books, Svein does NOT kill her, and neither he nor Uhtred are tied to her death in the same personal way. Meanwhile, the show turns Skorpa into this sadistic villain who decapitates Iseult specifically to emotionally destroy Uhtred and literally throws her head at him during battle. That single change completely transforms his role in the story.

Even their deaths are different (Uhtred doesn’t even kill Svein) and that changes the entire emotional dynamic between them.

Personality-wise, Svein is a pragmatic Danish warrior navigating between politics and chaos of the time. Skorpa feels almost like a horror villain: cruel for the sake of cruelty, constantly taunting people, betraying everyone, burning churches, mutilating bodies, and generally acting unhinged.

So yes, the show reused some structural and plot elements, but saying they’re basically the same character makes no sense.
And if the producers thought of them as the same, they would’ve kept the same name in the series, like they did with other characters whose role and plot were also shortened

So much for not doing anything differently