I have 'finally' completed the last assignment for the Stug IV. I'd say it takes around 4 hours, which isn't that long, but jeez was it frustrating. This is where this guide to tankers come in. See, when you can't get a vehicle, most of the time you have to rely on tankers to give you a good gunner position to use to complete this task. You can probably guess what happens (or has happened to you).
Anyway, on to the guide:
Rule 1 - Tank selection.
If you want to provide gunner seats for team mates, pick either a TD or a Heavy tank. Why? Becuase they come with a nice safe hull machine gun, or in the new Stug's case (if you have one), a radio controlled MG (a turreted MG you can use while in the tank). This is important becuase I lost count how many times I got shot off the standard top mounted MG, it's a death trap. Yes, you can duck, but that means you can't fire back, nullifying the use of that position. I'd also not recommended the light tanks, becuase they are simply too fragile and get killed easily, when spotted. Yes, unspotted, they are great, but so is every tank, and remaning unseen is best left to professional tankers, as in not the people this guide is aimed at.
Note: If you do wish to be a selfish player (personally I have no problem with this), I'd recommend the AA tanks, as it is a great way to show players what type of a player you are.
Rule 2 - Stay at the correct distance for enemies.
I'd recommend, after selecting the correct tank, to stay between 50-100m away from enemies. Why? Becuase you are far enough away to not be flanked (as hopefully your infantry have their attention), but also this is generally the most effective range of your weapons. Any further, and most times you can likely miss, or your gunners can't hit anything, rendering them useless, and that isn't fair to them. You want as much firepower used as you have access to as well, making you that much deadlier.
Rule 3 - Support your infantry.
Tied to Rule 2, you want to make sure you are supporting an infantry push. Why? Well, not only is your firepower helpful to them, they also distract those Assualt players who would otherwise try to flank you. They may also assists you if you get swarmed, which you'll really like. Plus, working as a team always wins matches, and that's what you want, isn't it?
Rule 4 - Try your best to keep your front to the enemy.
Now, this isn't always possible, as your tank, especially as it should hopefully by a TD or Heavy tank, can be flanked, sometimes no hard you try, becuase that day is just one of those days. However, you should at least try. Not just becuase your frontal armour is your best armour, or that a TD's gun faces forward, but becuase as a Heavy tank, turning the hull and turret together can bring your gun around faster, and also your hull machine gun is mounted their, and you want to bring them to the action too, for their extra firepower, right?
Rule 5 - Never abandon your tank (one exception).
This just hands the tank to the enemy. Every. Single. Time. Go down with your ship. It is also your gunners role to get out and either help fix you, or repair/build tank supply station. Only if you have no gunners (or effectively no gunners) and you need that tank supply station, can you get out, but beware of enemies and hop straight back in if you see them. A dead tank is better than an extra enemy tank.
Rule 6 - Never abandon your gunners.
If a gunner is repairing you, don't run away from them, even under attack. They'll keep your health pool up. Only run if they die, or they hop back in. Gunners are your best friend, treat them as such.
Note: These are rules I just thought of off the top of my head. If you have any more rules you'd like to suggest, feel free to mention them in the comments, and I'll make an edit adding them to the list. Hopefully, we can improve the experience of being a gunner of a tank together. I'll also make a gunner guide if I get enough requests.