Fly2cast in my option your bro is setting you up, he is the captain of the boat , he can put himself in target areas and leave you hanging jigging in in depth only a 3/8 jig would be suited for. Here would be one option,get one medium fast action 50 buck rod for a dead stick for heavey jigs and one medium light, fast action rod for pitching jigs then pitch your jig to were you have the first pass over the walleyes. This happens more frequent than you think it happened to me friday and every time we end up jigging, my friend was the captain he was in 9ft jigging working a shelf i was in 21 ft and to make thing worse i was in the current had to go to a 3/8 jig on dead stick and on my other rod a 100 buck StCrioux started pitch in front down current in shallower water. The captain caught more of the fish that day but not always got his ways down. Good luck, read up on jigging techniques alot of good information anglers have out there,get the edge,keep them sharp.