The answers can get somewhat complex because all fish, meaning crappie and baitfish in this example , don't do the same thing all the time. You are not experiencing fish staging early. Fish are dialed into the solar table. They aren't going to shoot eggs until the sun is right. Crappie start putting on eggs late summer. We are catching fish that are visibly showing eggs now. Some baitfish will move up into the warm shallows. Some crappie will follow them. One guy can be catching fish in 10ft. of water and another in 2ft. of water. The quality and quantity however, may be the difference. I have caught crappie in 2ft. of water at the Tenn. River while it was snowing. I couldn't believe it but it did happen. Some large fish are caught out of skinny water in the winter. One day they may be there though and the next they are gone or rather may have lockjaw. Shallow fish are going to be more moody, I believe because conditions are less stable the closer you get to the surface. Deeper fish seem to withstand a "little" more instability but even then big fronts can effect it all. What you are experiencing is fish moving up and down in the water column as conditions change. I caught a fish in 2ft. of water last Sunday afternoon. It happens.