Not frontal, central. Jimbe's fatass takes a lot of the screen, but he actually paralels Chopper more than he does Zoro.
What Oda does here is he is having the East Blue characters all in front. If you know how to read the spread, starting from Nami and going to Usopp on the other side, the East Blue characters all make a half circle in front, and the GL characters are all in the middle surrounded by them.
Among those East Blue characters Luffy is in the Middle, at his right there's Sanji and then Nami, and at his left there's Zoro and then Usopp.
What Oda does here is he is having the East Blue characters all in front. If you know how to read the spread, starting from Nami and going to Usopp on the other side, the East Blue characters all make a half circle in front, and the GL characters are all in the middle surrounded by them.
Among those East Blue characters Luffy is in the Middle, at his right there's Sanji and then Nami, and at his left there's Zoro and then Usopp.