running boards can have a big learning curve. First you have to know what depths the cranks you will be using run. Keep all your lines consistent. Meaning use all the same size/diameter of line on all your cranking rods. Or at least do the best you can to insure you fully know the depth of those cranks. Once you have that established you need to familiarize yourself with the area your running boards. Most of the big lake falls off pretty quick if your contour trolling the shoreline. So learn how fast it breaks so you know that if your boat is in 25' of water, thirty feet from the boat on the shore side it'll be 18' or whatever. And vice versa for the other side. I can run two boards out each side and two rods without boards for a total of six lines. It takes a lot of practice and patience. You'll still have an occasional fubar but the more you do it the better it gets.
If I'm contour trolling a shore I'll be running cranks at six different depths. Now if your trolling a big flat then it's very easy. Generally what happens when you hit a fish is it initially goes up. that will give you time to grab the rod and bring it to the back of boat over the motor. If it was an outside board you generally have to have your partner crank in the inner board on that side and real in the crank. Not always but usually. If it's the inner board your good. I have a rod wrangler that sits in a seat base right in front of the main motor. I mounted a rod holder on the top so if I grab a fish on a board I can stick the inner rod that isn't on the board in that rod holder with the tip way up. Then crank in the board, disconnect it and bring the fish in. Things don't always work the same way. So it just takes time, patience and practice.