Rule of thumb
占满整个战斗宽度两排，后排全炮兵；前排左右各 "骑兵 flanking range" 数量骑兵，其他为步兵。
例如战斗宽度 40，flanking range 为 5（骑兵）,则部队组成（适用于后期）：
骑兵前期各项均强于步兵。但后期骑兵冲击 / 士气（shock)比步兵稍强，而火力 (fire)比步兵弱得多，总体（1对1）战斗力比步兵弱。不过骑兵的 flanking range 是步兵两倍。所以后期骑兵一般只需要能够在战线两端能填满 flanking range 的数量即可。
flanking range is possible attack targets. Units still only attack 1 target at a time.
Units in the front row can attack any enemy unit within their horizontal flanking range. Normally they will only engage enemies that are directly ahead of themselves, but they can sometimes execute flanking attack regardless if it will be more effective at reducing the enemy's combat ability. This typically occurs if the unit is facing an enemy artillery regiment or a particularly outdated unit; in this case the unit may choose to attack the flanks of a stronger enemy unit nearby. Artillery are the only units that can attack from the back row, but they will only deal 50% damage from that position.
Flanking range is how far to the right or left a unit may attack. At game start it is one for infantry and artillery, and two for cavalry. This of course increases over time through techs until it finally reaches two for infantry, and five for cavalry and artillery. Wounded troops have less flanking range: you lose 25% flanking range for every 250 troops missing from a unit.
Flange range：基础值初始 1 / 2 （步兵/骑兵），随科技发展增长，最后 2 / 5. 受到 flanking range modifie 影响。
When a larger army is deployed the infantry will only fill the effective combat width of the smaller army's infantry + cavalry, regardless of flank range. Example: You engage the enemy stack of 8/4 with a stack of 14/2. The enemy will deploy their entire stack of infantry in the middle, and two cavalry on each side. You will deploy exactly 12 infantry to middle, one cavalry on each side, and then one infantry on each flank after the cavalry. You'll notice this is not the most efficient setup we can use; only the cavalry flank in this scenario. Optimally our troops would be deployed with all 14 infantry in the middle and one cavalry on each side. This setup allows both the infantry and cavalry at the far ends to flank properly. Despite this, the deployment logic will use the former, not the latter deployment. The only way the player could use the latter scenario would be to have all 14 infantry enter battle, and then have the cavalry enter a day later. To break it down even further let's use some visualizations:
Neither army has cannons. The enemy infantry deploys to match the length of the player cavalry + infantry.
Only the enemy has cannons. The only difference from #1 is that the enemy spare infantry are instead deployed to the front.
Only the player has cannons. The enemy spare infantry are back in the backline this time, but the player cannons have done something interesting. The cannons fill the player backline only as far as they can flank the enemy, the rest getting pushed to the front for additional flanking. You can see that even though the enemy army could deploy its spare troops to damage the frontline cannons it doesn't. This is a good example of when you can see the faults of the game's deployement logic.
Both armies have cannons. The player army deploys as many cannons as it can that hide behind the infantry + cavalry. The rest get deployed to the frontline.
Now that we know how the game's logic deploys cavalry, how many do we use? To make maximum use of flanking range without extreme micro-managing we can just multiply the cavalry flanking range by two. In short, Techs 3-18 is four cavalry, 18-23 is six, 23-30 is eight, and 30+ is 10.
I'd like to repeat that the explicit purpose of this post was to explain flanking range, how it works, and how you would maximize it. I'm not arguing for or against certain army compositions, how useful cavalry are etc. I hope this post clears up some misinformation people have with flank range how it works and maybe you learned a bit about how army deployment works. There's a lot of neat tweaks to the combat not covered here and I urge players to check out the excellent land warfare page (heads up, a few small things are outdated, but great otherwise). If you have any questions or see any corrections please let me know.
围城 (siege) 炮兵加成最大为 5 (最后一个 age 的‘Napoleonic Warfare’能将其提升到 8）
The bonus is equal to the total number of artillery regiments divided by (fort building level + 1)
A single regiment of artillery will always give at least a +1 bonus, regardless of fort level.
Each 1000 artillery soldiers count as 1 artillery. e. g. having 10 regiments with 100 artillery each is the same as 1 regiment with 1000.
即对于 8 级要塞（建筑等级为4），需要 8 * (4+1) = 40 队（40，000人）炮兵则能获得最大的 +8 围城炮兵加成。
步兵：火力 > 士气 > 冲击
骑兵：冲击 > 士气 > 火力