Yeah... having fully regained regiments, helps. Also over some number, your army size stop to matter, as only part of your regiments will take part in battle (i think it is 32 regiments in two rows, meaning 16 in first row, and 16 in second... or something like that.) Additional regiments only makes reinforcement for those. So making doomstack does not realy help much in battles - it is better to keep reinforcement in adjactened provinces, just to bring them when they are needed. Also bringing armies bigger than 50k is not helping you as you will suffer atrition greatly from too big stacks. Also, the second row, only takes part in fire phase, so best armies are around 16-20 k, with at least 6k calvary. Calvary is better in the battle due its attack multiplier, being higher than infantry (think it is around 3-4, meaning that your calvary with 1 shock is three-four time better than your infantry with shock 1). So if you have as much calvary as possible, while having the mixed arms bonus, which mean 7 calvary 9 infantry for 16k unit, it gives you the best possible army mix. So, if so you need only to bring some units that will be ready to help it in battle when it start loosing men. When later on, fire comes to the battlefield, you can add 16 cannons in the back row - but as artilery is making army movement slower, it is best to keep it in another unit, and bring it to decisive battles. Artilery being in back row, is giving a bonus to defense and attack from the back row, meaning, you will fight in battle more effectively with artilery. Not artilery units in the back row does not help in battle i think, so it mean you waste place not using artilery - and if battle is important, it does count, regardless of artilery strength.