This was my thought.
A second thought: If you had images of, say, Madonna and Child by Leonardo da Vinci, Michelangelo Buonarroti, Titian, Botticelli, and Caravaggio, would you try to get the “ideal” image by combining them into one picture somehow? No, you appreciate the different styles of each master, and, perhaps in studying them, note what each uses from the others, or how they offer a special detail, and so on.
The Gospels are fine as they are–unless you desire to know the “real story” of Jesus, in the sense of a modern biography–and for that the Gospels will forever be inadequate, because they are telling a different story, a story of faith and salvation, using the rules of a different genre.
For example, from one line by Luke (that Jesus was about 30 when he began his ministry, Luke 3:23) and the fact that John speaks of three Passovers (Chapters 2, 6, and 13-20), we get the “fact” that Jesus was 33 (or possibly a few years older or younger) when he died. It has been argued that, according to John, Jesus is shown as nearly 50 at his death–the temple (of his body) was being built for 46 years (John 2:20), and the Jews say he is “not yet fifty years old” (John 8:57), rather than, say, “not yet 40” when they try to stone him. Such an age is not against anything we find in the Bible–we never learn the full length of Jesus’ ministry, or the exact age he started–but it is not the generally accepted tradition. All such details would be required for a modern biography–and we simply do not have them.