RV suffers from something all of bardin’s carreers have, to some extent: Lack of a “kit”. His talents and weapon choices are, basically, only a loose assortment of picks, rather than being able to build a concept.
Is also doesn’t help that his passive skill is very limited in its utility: On Legend and above, due to the abundance of specials, you and your team almost drown in supplies, to the point where you can’t even reasonably use all the potions, bombs and ales you get spewed at your feet - but during end events, it becomes noticably more random how useful the skill is and during lords, it becomes completely useless. That’s a big problem for me, because especially during, say, a fight against Rasknitt on Legend or Cata, where is additional supply drops would be a true boon to the team, they are absend, essentially nullifying his carreer passive and restricting it to situations where constant availability of supplies isn’t even that much of an asset.
What would be a solution? First of all: Splitting drops between specials and elites. I mean, we already have a counter-gimmick on Grail Knight and his strength pot, why not do the same for RV? Let the ammo drop on special kill, and let everything else from his talent row (ale, potions, bombs) drop on killing elites. Increase ammo drop to 20% max ammo and leave it there, and let Bardin choose between ale, potions and bombs with different elite-kill ratios (e.g. 5 for ale, 10 for pots and 8 for bombs, something like that).
Give RV access some kind of grudge-mechanic. I mean, BH gets DR for special kills and elite kills, why not give something like that as an option for Bardin, but make it either attack speed or a small power boost. This could even be its own talent row with different options (attack speed, movement speed, power or crit chance). This would easily give him more of a focus towards special- and elite killer, while allowing you to build around different weapons and mechanics more easily (stacking AS is good for melee, more crit chance allows for building around Hunter).
I am still advocating for RV getting an option for stuff doing additional things on him when taking the corresponding drop-talent:
When choosing bombs, his regular bombs should make enemies bleed, and his fire-bombs should last 100% longer.
When choosing potions, each type of potion could have additional effects (strength pot: 50% DR; con-pot: +25% crit chance, speed pot: generates 3 temp healh pers second), or simply heal him for 30 true health (no wound removing).
His ales could also increase his (and only his) headshot damage, or stack 4 times instead of 3 just for him.
I would also advocate to give him more throwing axes to make them viable on RV (they are actually pretty solid on Slayer).
RV isn’t too far off, but it’s little wonder why, from my experience, RV is amongst the least picked carreers in the game (and 90% of the time, he is just an ale dispenser with a handgun).
RV just needs a true kit to work with, and let’s face it: access to more ranged weaponry. I truly hope the new engineer masterwork pistol will be available to RV, which will open up a new playstyle. But I am also still stronlgy advocating for giving RV access to BoP, which is absolutely lore-friendly (there is, iirc, a model called “Master Engineer with Brace of Pistols”, which is, admittedly, the master engineer - and more of a bag of pistols than a brace -, but there’s no reason why it shouldn’t be available to RV, too), something that would only need a handful of new models, as the mechanis are already there, and it would give RV, again, access to a completely new playstyle.