Self-Propelled Howitzer is one of the scrapped or not finished Vehicles not-featured in the game. It only can be seen on a promotional image. As with everything else that did not make the final version, the vehicle lacks a skill image.
One possible reason of being cut-out could be lack of resources allocated needed to fabricate one more attack, namely parabolic artillery strike. On the other hand, the assault cannon could be lowered and fired just as any other Launcher, or the shot could have behaved like that of a Grenade.Having enough attack vehicles in the game, developers could also have decided to replace artillery with air strikes carried out by Fighter Jets which are distinct for a unique way they are implemented in gameplay.
On top of that, it's not really clear why the vehicle was included in promotional material. Either developers had plans to finish it, or just wanted to tease the players.
- It's not the only early XX century material seen in the game, which could probably mean than one of initial concepts was placed in a corresponding era hence some of the stylistic elements, but then revoked in favour of a modern one, giving a strange feeling visual mix.