From Supreme Commander Wiki
All T1 mobile artillery have the characteristics of a high firing angle, giving them the ability to shoot over obstacles otherwise known as indirect fire. They also have great DPS for their mass cost.
[edit] Factional Differences
UEF Lobo: Has the highest HP and reload time of all the other faction's equivalent. Also is equipped with shellcam, or line of sight of the detonation area. Shells split into 5 smaller ones, much like the Seraphim Zthuee. Has the same movement speed as the Cybran Medusa but faster than the Aeon Fervor and the Seraphim Zithuee.
Cybran Medusa: Has the lowest HP and third longest reload time of all the other factions equivalents. Has the lowest DPS, but it's shell has EMP, or stuns it's targets. Has the second highest mass cost, but is faster than the Zithuee and the Fervor.
Aeon Fervor: Has only 10 more HP than the Medusa, but boasts the highest DPS and rate of fire. It is also the cheapest T1 mobile artillery in terms of mass(along with the Lobo). Despite these advantages, the Fervor is cursed with a very small projectile damage radius of 0.5,the smallest and rendering it somewhat less useful against mobile targets and best used against structures or slow-moving units.
Seraphim Zthuee: Has the second highest HP but with the highest mass cost of the four mobile artilleries, being more expensive than the Aurora and Mantis, 2 mass cheaper than the MA12 Striker, and equivalent costs with the Thaam. Despite this, the Zthuee is arguably the most effective T1 mobile artilleries for several reasons. It has earned the nickname "Fobo" for 2 reasons(depending on who you ask). Fobo is a play on Lobo, or the floating Lobo, because out of the T1 mobile artilleries, only the Zthuee hovers, and because it's shells split into 5 smaller ones like the Lobo. Another reason is a Play on Fervor and Lobo. This could also because it combines characteristics of both(high rate of fire of the Fervor and damage radius of the Lobo).