They do have a lot of overlap in certain respects --- scary animal motifs, motivation to fight crime from a tragic and violent death inflicted on a parent (both parents in Batman's case, a parental figure in Spider-Man's case, but still), using intelligence in the forms of advanced gadgetry and psychological manipulation to overcome nominally superior adversaries (Batman makes his enemies afraid to face him, Spider-Man makes them so angry with his quips that they can't see straight and careen headlong into their own defeats), enemies include a lot of the criminal underworld of their respective cities and many who could be considered twisted reflections of themselves . . .