You might think about straightening out those 2.4 antennas just a bit if you can. How about you bring the middle antenna up about three inches and then slant the 2.4's in?
I think the best configuration is 5.8 pointing straight up, 2.4 pointing straight down (or down and out a bit). This would allow him to keep them all on the same plane, with good separation between them, wouldn't it?