Modern Combat transports players into the midst of a high-tech war between the current-day Chinese and U.S. militaries. Incorporating all-new factions, units, doctrines, gamemodes, artwork, music, maps, and singleplayer missions, we aim to craft the most immersive and enjoyable strategic representation of 21st-century combat possible on the PC.
105mm guns don't serve as anti-tank anymore, because they can't penetrate modern armour. Instead, they're used in infantry support role, clearing fortifications and destroying light vehicles.
That is the exact purpose of this unit :)
Caliber doesnt determine everything. Look at World War 2. the Soviets threw a massive 122mm gun on their IS-2 Tanks and it was little better than the 88mm on the Tigers.