Overall strategy[]
Compared to Arquebus Infantry, Musketeers now have better range, as well as a slight attack bonus compared to their Arquebusier precursors, as well as the advantage of having NO minimum range, making them more powerful in comparison to their matchlock-wielding forbears. They are still weak if facing enemy cavalry - fast cavalry especially - along with cannon.
Use these units to hold battle lines with the assistance of your other units - pikemen and halberdiers, and to thin out your opponents' own.
It is noteworthy that Musketeers are not available for the United Kingdom at any point in time, but they instead get the far superior Redcoat infantry, which has a fairly quick rate of fire.