Andy Serkis called Tom Hardy “magnificent,” and you have to think that he has a unique perspective on this film, the relationship between Venom and Eddie, and Tom Hardy’s performance.
Andy Serkis famously did this as Gollum/Sméagol in The Lord of the Rings and The Hobbit trilogies, so he knows a thing or two about it and can appreciate and help with that element.
Tom Hardy obviously plays Eddie Brock, but he also voices Venom, two characters that are in many ways one; two sides of the same coin.