Leonardo being the leader has consistent across all the franchise; his characterization, in fact, has generally been the most stable all the adaptations in terms of being the more serious and straightlaced of the brothers, while the others have more variability; Michaelangelo, for example, while always the more fun-loving one has ranged from goofy and not very bright surfer dude to being smart but simply intellectually lazy and having more interest in goofing off than work. Raphael, with the exception of the 1987 animated series (the one most of us of a certain age know the best, being the first) has always been the berserker of the group, whether due to frustration at not being the leader, being a Blood Knight and loving combat, to just being angry at the world.
If you had to summarize the group across all incarnations it would be Leonardo is the leader and the serious one, Donatello is the smart one, Michaelangelo is the most laid back, and Raphael is the angry one. At best, Raphael has been second-in-command and sometimes takes charge, or thinks he should be in charge, but always cedes leadership back to Leo.