This nerf is another example of bandaid fixes and lazy design crumbling at some point.
First: The +50% Bonus for Plates and +100% Bonus for Shield Extenders should have never been given, instead 3200mm Plates and XL Shield Extenders should have been made. Why? Because those would have been required (much) more fitting resources, thus asking for sacrifice to get their power instead of giving a bonus for free. You would have to downgrade something else to fit them. High PG/CPU requirements would also have made sure that they can’t be fit on Cruisers and to BC/CS only if they sacrifice basically everything else (the heavy weapons, MWD+MJD, CapBatteries…).
If they had made it this way, the pilot had to decide: I want dual 3200 Armor Plate, okay, so I can’t fit HeavyNeuts any more. Or Smartbombs. Or a HeavyCapBooster. Is it worth that? Or do I need these, then I can’t fit MegaPulse Lasers any more and have to go with DualHeavies, sacrificing Range/DPS. Or I need to fit PG-Rigs instead of Capacitor/Armor Rigs. Choices, good. Free Boni, bad. And a Massmultiboxer who needs max-tank to be able to switch to the right client in time would probably need to make quite some concessions to get that, lowering the performance of the whole fleet and making it more engagable by others at the same time. One strike, two hits.
Second: The main problem with Marauders currently isn’t their buffer. Well it might be in PochvenPvE, but seriously, nerf Pochven ISK printing and you have solved that problem. Their main problem in general is their insanely oppressive combination of DPS+projection. Marauders should excel in standing their ground, sieging a position. But they shouldn’t have any range- or application-boni to just eradicate ships even from far away. Removing all Range boni but only giving them DPS and Tankboni would give them a MUCH better spot in the ship meta, balance wise, because FactionBS would have a way to perform comparable again by being more mobile and reaching far away targets or mission/site goals much more easy while moving towards the next ones… And other, mobile PvP ships have easier ways to outmaneuver them, forcing them to reposition (by unsieging…), which makes them more vulnerable and less oppressive.
Edit: Ah, and before I forget about it: If “Triple Ancillary XL ShieldBooster Fits” are a problem (thats why you nerf the CPU on the Vargur, right?), DO THE LOGICAL THING: allow only ONE Ancillary Shield Booster per ship, like… you know, Ancillary Armor Repairers? Ancillary Remote Armor Repairers? Ancillary Remote Shield Transfers? You see a damn pattern? Allowing to fit multiple of these has been a huge imbalance since the implementation, and them running totally capless while Ancillary Armor Reppers need paste AND cap is another. Fix that already, you will get rid of another unnessessary exception, making your game more balanced, more easy to understand and learn for new players. (See: K.I.S.S. method).