The Somua SM is a French Tier VIII Premium heavy tank with an autoloader. It is to the AMX 50 B line what the AMX M4 mle. 49/Liberté is to the AMX M4 mle. 54 line – similar gameplay with a couple of differences to pay attention to, but all in all a great choice if you're a fan of that type of gameplay.
The AMX 50 100 is famed for two specific traits: the autoloader and the good mobility, allowing it to keep up with medium tanks. The Somua SM's mobility is on par with other heavy tanks but far weaker than the other French vehicles. What it got instead is improved frontal armour, both on the hull and the turret, allowing it to surprise its opponents with unexpected bounces. The side armour is quite tough as well, angle your tank a little bit to increase the effective armour value.
Let's have a look at the most prominent feature of the Somua SM, its gun. With five shots in the magazine and a fairly quick reload time between those rounds, you can seriously damage or even destroy same-tier vehicles in a short amount of time. A downside of it is the mediocre accuracy; forget about sniping at distant targets. Compared to the AMX 50 100, the reload time of the magazine isn't that long. Retreating into cover isn't that difficult because while the forward top speed is average, the backward top speed is pretty neat.
As with any autoloader in the game, it relies on landing as many hits as possible, which is why we're focusing on stabilisation and aiming speed. The Improved Ventilation will grant useful bonuses for accuracy, aiming time, and reload speed.
As with most vehicles, Repair is the go-to skill, especially for vehicles with autoloaders. In the end, the last thing you need is destroyed tracks while you are retreating to reload. Snap Shot, Smooth Ride, and Brothers in Arms will all contribute to making your gun more reliable.