Well, I wanna talk a little about berserkers. What if they armour has a specific modules like armour of heavy and tech guys? If I remember that piece of lore right, berserkers fightings on arenas of Anu settlements, being drugged with some various strong chemicals. But in-game we have only big drugtank on back of berserker’s armour. And this is why their armour provides that speed-bonus and a little accuracy disadvantage as I understand. But what if that tank could contain various drugs? I.e., berserker’s armour would not provide bonus of speed anymore by itself. But it can be equipped by one of several modules. It can be module with old jolly speed boosting chemicals, other variant can be defensive chemicals - providing damage resistance or armour or using to heal some gen. health and limbs. Or, it can be offensive drug providing some bonuses to damage or shred or something else to be more deadly.
P.S. I don’t know about type of bonuses. Maybe they must be temporary like additional abilities, maybe constant. As I understand, berserkers are constantly drugged in combat with they current armour. Well, they have really big containers with chemicals on their backs. Also, we can adding one-using injectors with this chemicals as like as we have frenzy stimpacks in game already.