So if you were in a training exercise and wanted to know where the enemy was hiding you might send one vehicle into the open. Once they're fired on you now know where the enemy is. That vehicle would be a Sabot Sucker. You might also use a sabot sucker to draw attention in a different direction so you can sneak around another way, etc.
Many times at the National Training Center at Ft. Irwin, CA active duty Army units are assigned a National Guard unit to go through the rotation with them. It's common practice to send the useless National Guard units first as sabot suckers. NOTE = Anyone to be used as a sabot sucker will be decieved into thinking their role is critical when really its a diversion.
National Guard Captain: YES! We've been training all year for this, we won't let you down.
Army Captain (under breath): see ya Sabot Sucker.