They're doing some things right. Shooting and scooting is something an American mortar section would do as well- particularly against the Soviets who had good counter battery systems.
What they're lacking is a good FDC and perhaps some good crew training. The most effective method of employing a mortar (supposedly) is the direct lay. It's as simple as it gets. You lay your gun in directly on the target using the gun's sight to look directly at the target. You estimate the range as best you can, set your charge and elevation accordingly and drop a round. You see where the round lands, adjust the sight to that point and then T and E the gun system back to the target- which should bring your round on line. You make your range adjustment and that next round should land very close to the target.
A skilled mortar crew (without an FDC) should be able to put at least the third round on the target and the second round very close. This could be done in a matter of a couple of minutes- the longest bit being the time of flight for the round. But let's say the time of flight is about 30 seconds (for a good round number) and we'll give the gun crew twenty seconds to make adjustments (which is a piece of cake for a good gunner). You fire your first round, 50 seconds later, you should be dropping your second adjusted round. If you care to stick around another 50 seconds you can drop a third and even more accurate round- you wouldn't have to wait to see where that one lands. So we're talking two minutes here. You take that mortar out of action in a matter of seconds and you're hauling a$$ hoping the Americans haven't fired off a shot yet- maybe three, three and half minutes. But this is keeping in mind you have to get well out of the area. An artillery round has a nice little kill radius and after three successive shots that counter battery would have you pegged pretty good.
If it were my crew, I'd hang around long enough to adjust one round but I'd fire off multiple rounds with that data- ie my second shot would be my fire for effect. You could get some reasonable accuracy and get a few rounds on that spot as well very quickly while keeping your survivability to a calculated risk that would be acceptable vs the enhanced likelihood of inflicting casualties.
Of course, for direct lay the gunner needs a clear line of sight to the target. Failing that, they need a good FDC and FO. They'd be much better off keeping their powder dry until they got their sh!t together than exposing themselves to this willy nilly round lobbing. A mortar crew can be drilled to a very high standard without ever firing a shot. They can be drilled inside a house even. The only thing different from a real fire mission is actually dropping that round down the tube. A good FDC can be drilled in like fashion.
These guys are just sloppy. If they cared enough to be more effective, they could be. It seems to me like a jihadi mortar crew is more a way for them to "count coup" and do something manly (that is less dangerous than a direct attack) than anything else.
Not if they're in Strykers. They've got to set up and break down outside the vehicles with every mission. IMHO, the Stryker 120mm mortar version that can'r be fired from the vehicle is the most questionable weak reed of the bunch.
-archy-.-