An almost unseen effect on your army happens when you take higher ranked generals in multiplayer battles, which is a boost in morale. Taking a 9 star general will allow your troops to survive 20-30% longer in heavy combat situations and make it viable to use militia in your front line. If you also include foot guards in your army, then your units will fully deplete before routing.

Certain terrain will cause a drop in accuracy for your musket-armed infantry, mainly dense forests. On Italian Grassland, for example, if you take the center forest you can waste your enemies bullets just by sitting in the trees. I would still watch out for when the enemy decides to get up close, though.

Other ways of wasting enemy ammo is by hiding troops behind stakes or taking advantage of hills to block the enemies line of sight.

Dismounting dragoons has some interesting tactics available. They will always dismount fresh and fire 2 ranks deep, and will be very viable in melee combat. They can be useful for house engagements or fighting in the streets.

Grenadiers are rarely used because they are more expensive and have less men than line. Since their grenades got nerfed from Empire, many ignore them completely. However, grenades can be very deadly to units that are pinned in melee as they cause casualties & a morale drop. You can also throw grenades over small hills and even your own units.

Grouping up your units in a formation other than a long, thin line will allow you greater flexibility and manouver in combat. This is especially useful when defending terrain features like hills since you can take advantage of line of sight to keep your troops from taking damage and possibility set you up for an effective charge.

Also, setting up your line infantry in columns and forming multiple echelons will allow for much more effective micromanagement which is very useful for an aggressive player. Once you are close to the enemy, you can deploy your men into fighting positions and engage the enemy's weak points.

Reload Skill does not have a large effect on how fast a unit reloads. However, there is a point between 70-80 reload skill where a units rate of fire increases by 50%, which is exclusive to foot guards.