Id just like to say in regards to playing the objective, that there is one other major factor as to why you might NOT want to fight over the objectives directly:
That reason is map control. This is something I find is very rarely understood in War Thunder. In essence, gaining map control is the act of being able to take and hold positions that provide the strongest advantage over the largest portion of the map possible, giving you the best firing lines and ability to cover as many areas as possible with the least amount of movement or relocating.
These positions are not always where the caps themselves are. In fact they are rarely on a cap, sometimes they can be around a specific cap, but not always. ESPECIALLY on the single cap maps.
These are positions that you absolutely WANT to take and hold. Some of them are so strong that a single tank there can win the entire game, and a lot of these positions are not actually on cap points, some arent even close to any of the caps.
Not all maps have positions like this, but many do.
For example: flanders, most people like to go C. But Map control is earned from the areas around B, from the areas around B cap you get free side shots into EVERYONE fighting over C, while they will struggle to get return fire on to you because of the cover you can get from B cap. It also allows you supporting fire into A, and if you can push through B onto the enemy side of the map you can basically pin down anyone coming out of both of their spawns. You WANT to take this position even if its a single cap mode with only the C cap in play.
Another example: Maginot. Again on the single cap mode where the only cap is in the city, I dont even go there. I flank around and go to where B would be. Taking this position allows you free side shots from cover into the giant open ground that the enemy has the cross to get from their spawn to the cap at A. Even if the enemy caps A initially, they wont be able to reinforce it because they are pinned down before even getting to the city, allowing your team to cap it back and win.
On the 3 cap version of Maginot I find the C cap provides the best map control if you can push past it into their side and get below their ridges, allowing you to cover 2/3 of the entire map.
On the flip side to this, you need to pay attention to the areas that DONT provide map control. Normally these are areas that are physically seperated from the rest of the map, providing limited ability to effect other caps without having to drive around. Things like A cap on Finland, the C cap on Tunsinia (in the town), or as mentioned before, the C cap on Flanders.
Many of these areas dont allow you to effect other areas of the map, and you must drive through choke points to get to those other areas that can be easily supressed.
Again, not every map has these positions. Mainly maps that have all their caps physically seperated from each other, sweden and Alaska for example are two maps that have limited abilities for map control, so all three caps are fairly equally important.