Although Mark follows a general chronological approach in recounting of the story of Jesus (as do the other gospel writers), he’s not married to it. More to the point, he never claims to be. So, it’s a serious error to think that Mark somehow isn’t inspired because absolutely every detail isn’t arranged chronologically. Though we might prefer it that way, we can’t fault him or any other biblical writer for not writing in the way we would like them to.
Furthermore, when you stop and think about it, what have you ever read or watched that was is strict chronological order? Very little, would be my guess. Novels regularly feature flashbacks. Even the history books I’ve read tended to deal with eras and ideas more than rigid chronology.
The point in all of this is that writers have more in mind for their audience that strictly showing them in what order things occurred. That’s not unimportant (Jesus’ baptism has to come before His temptations as does the crucifixion before the resurrection), but that’s not all they want to tell us. In Mark’s case, he wants to emphasize the opposition Jesus experienced from the Pharisees and religious leaders early in His ministry, so we have a section in 2:1-3:7 that features five stories of conflict. Did they all occur one right after the other? It’s doubtful. Does Mark claim they did? Of course not. Look at the transitions he uses and it’s clear what links the stories isn’t chronology (“Once again” – 2:13, “Now” – 2:18, “One Sabbath” – 2:23, “Another time” – 3:1). Does any of that sound like he’s following a rigid timeline?
In the end, all of the gospel writers do the same thing—they tell the story of Jesus in their own unique way. Matthew is writing to a Jewish audience so not surprisingly he fills his gospel with Old Testament texts that find their fulfillment in Jesus. Luke is writing to “most excellent Theophilus” (probably a Roman administrator) to extend his knowledge of Jesus and His way, so rather than speaking of “the abomination that causes desolation” as Matthew does for his Jewish audience (24:20), he simply says “armies” (21:20). And so it goes. It’s no different than if you had four friends tell you the story of Jesus. They would all tell you the same general story—but they would do it their own unique way—emphasizing different things. And sometimes their emphasis would take precedence over strict chronology.