Actually there are LSOs as well, but the S is for Safety instead of signal. For LAMPS ops, there is no LSE on deck for the exact reason you guys are complaining about (and rightfully so). Since we have to get your "probe" into a 3x3 "box," and not just put our gear somewhere in a big circle, it complicates things to have guys on deck (except during a RAST operation, but even then, they run inside once the helo is hooked up on the cable in the hover).
The LSO takes control of the deck from the tower, is responsible for telling the bridge when they've jacked up their wind hunting circle, and actually gives the green deck to the helo. On landing, he also helps conn the probe into the trap over the radio. Once recovered and shutdown and waterwashed, a LSO has to straighten the aircraft so it's lined up to get into the hangar. Probably one of the most bizarre evolutions to see, as the tailwheel looks like it's about to pop off the bead. All the pilots should be LSOs on cruise, and usually a couple of the maintainers are LSO-Traverse only (Chief, LPO, and day/night check supe).