Compared to the very first days of AOE 4, grenadiers is more effective againast heavy units and less effective vs light armoured units.
The conclusion is they are in a fine position, see below:
Grenadier’s damage logic: They have a splash damage reduction rate based on the distance from the direct target. When attack a unit, the damage will be reduced by certain amount.
Stage 1. At game launch: Grenadier have 18 attack, 4.8 range and the damage reduction rate is 100%/75%/50%.
Heavy Unit: When attacking heavy unit with 8 armour, the actual damage it take is 10(18x100-8), while the unit within the second radius takes 5.5 damage (18x75%-8), and the unit within the third radius takes 1 damage (18x50%-8). Overall it’s 10/5.5/1.
Light Unit: as calculated above, light unit with armour of 3 takes 15/10.5/6 damage.
Analysis: with a decent attack on both armored and unarmored units and long range (can stay at a safe distance from the cavs), grenadiers almost have no direct counter from the core roster.
Stage 2. Season 3: There is a patch (season 3) that massively nerfed grenadiers. Grenadier now have 16 attack, 3 range and the damage reduction rate is 100%/66%/33%.
Heavy Unit: with armour of 8 takes 8/2.6/1 damage.
Light Unit: with armour of 3 takes 13/8.6/2.3 damage.
Analysis: Now grenadiers are massively nerfed (damage changed from 10/5.5/1 changed to 8/2.6/1), almost useless against armored units. Mostly because unit in the second radius takes 54% less damage, and it’s the second and third radius that matters in mass battle. They are still effective against unarmored units, but what China lacks is not the ability to deal with light units. In late game, China relies on handcannon and NoB to deal with heavy inf and cav, but they are both gold intensive and easily countered by culverin and mangonel. On the other hand, China heavily relies on gold mine as a means to acquire gold. The consequence of this chain effect is, China cannot effectively deal with armored units in the late game.
Stage 3. PUP: In this PUP, the devs have seen grenadiers have not been used for an entire year and decided some change. Grenadier now have 12 attack (changed from range to siege), 3 range and the damage reduction rate is 100%/66%/33%.
Heavy Unit: with armour of 8 takes 12/8/4 damage.
Light Unit: with armour of 3 takes 12/8/4 damage.
Analysis: Compared to stage 1, grenadier is more effective vs heavy and less effective vs light. So, the correct way of using them is to counter mass heavy inf and cav, and the correct way of dealing with them is to: 1. use split formation with fast melee units 2. use light range units 3. use mangonels. Please be aware, grenadiers now have less range so they cannot stay in a safe distance and have to form a cluster in order to attack, which make them vulnerable to mangonel shot. As for now, grenadiers make a good compensation against heavy, and not OP because there are plenty of ways to effectively counter. Obviously it’s not an auto-win like someone always claims, but require more experience and skill to deal with (if you call ‘left click select the mangonels and right click on the grenadiers’ a skillful maneuver. That almost require 2 APM). For a unit that requires 3600 more resource to unlock, it’s definitely a proper position.