Serenity. T3 Aeon land unit designed to engage over long range.
Sprite striker. T3 Aeon land unit designed to engage over long range.
Absolver. T3 Aeon land unit designed to engage over long range.
While yes, all three units have their own 'flavour' in both how they function and how they are used, the overlap is still very considerable, especially as these are the types of units that see very little action in normal games. As it currently stands they step upon each others territory too much, in some situations they do this nearly to the point of effectively being the same unit, if the point of having these units is for unit verity, then its not working.
There are two ways to remedy this, either consolidate the units into two or maybe even one unit that fits the combined roles. Or differentiate the units more than they currently are so they overlap much less.
If taking the former, then I see the best action is to remove the Absolver and give its anti-shield effects to the Serenity. Giving the Serenity a reduced base damage but a grater damage against shields. This would allow it to still maintain its role as an artillery anti-structure unit as it can shred through shields more effectively than other factions mobile T3 arty, but deal less damage to the units and buildings under the shields, equaling out in the long run.
If the latter, reduce the range and speed of the absolver, buff its hitpoints and rate of fire, turn it into a unit to be included in the front lines of attacking armies so that it can help take down shields to allow the harbingers to attack everything underneath, both units complimenting each other.
Aditonally nerf the Spirte strikers rate of fire but buff its damage, to more encourage hit-and-run or VIP assassination attempts with it.