The Oliver Queen of the Smallville TV series works with Clark Kent even before Clark has become Superman whereas the Oliver Queen of the Arrow TV series meets Clark's cousin from the parallel universe of the Supergirl TV series. Neither is the original Oliver. Two adaptations could not be more different.
Smallville has perhaps four kinds of characters:
familiar and recognizable, e.g., Clark and Lois;
the same only in name, e.g., Pete Ross, Cat Grant, the two Hamiltons; Glorious Godfrey;
new, mainly Chloe;
new characters in old roles - Lex's father, brother and half-sister.
I think that too much happens in Smallville even before Clark has become Superman.