Light Artillery

Overview
Light Artillery units are similar to Mortar units, but available for production without Nanopods. Compared to the Mortar, Light Artillery:
 * Has further range (2-5 rows instead of 2-4);
 * Does more damage
 * Has fewer hitpoints

Nevertheless, a few of these to be used as counter-artillery is not a bad investment, due to the fact that this unit has the most damage for a non-premium 2-5 range unit. You can earn one during the Siege of Marin.

This unit is superior in damage to the Aries and is an improvement over the lower-level Artillery unit, the Mortar).

This unit is inferior in damage to Mortar Trucks and Heavy Artillery, but it still has advantages over both. It has more range than a Mortar Truck, and is not bought with nanopods unlike Heavy Artillery.

1.2 Comparison between Mortar and Light Artillery
Now let's check the differences between these two Artillery Units.

The Light Artillery is weak against /Shell Units while the Mortar is not. Neither unit has a dodge bonus and both use indirect fire. You'll have to reach Level 20 and to build a Gun Foundry, to be able to produce Light Artillery units. To get the Mortar, you must spend 6 Nanopods. The only one advantage of the Light Artillery is to have a larger Range, so it can shoot at units from the third row.

Note: While the comparison takes into account the raw data, there is a very specific note which has not been mentioned. Mortar squads cost Nanopods to train, while Light Artillery do not. Late into the game, the Mortar Truck, a more robust form of the Mortar with infinite ammunition, becomes available and can be purchased without Nanopods. Furthermore, you will have to train at least a few of the Light Artillery units for quests; you need not ever use them.