I am mentioning that because the discussion is kinda pointless. The game doesn't need a perfect balance between "classes".
If you think the game doesn't need balance... Why you care about ppl that think so? It's something I always wonder... If you
like to play in a given way what you should be asking is to have gameplay elements you can interact with. If you scroll up and actually read the very first post is about that... This game offers those elements, that's no problem.
Such balance arguments as the above one are however inconclusive
Really? Well I will quote yourself to highlight how, in reality, you are caring about balance and already showing examples of what you also perceive as broken:
And I am sure 2 lone-wolf ranged/dagger rogues could finish this game with ease just by using the barrels and environment.
If you are sure... Why didn't you do it? Have you checked, in your reassoning,
how many turns it would take for them to finish a fight? There is nothing complex about evaluating balance... Just requires ppl to look for the right magnitude and just playing the game with different configurations. I challenge you to play the game with the following Lone-wolf Duo: Hydro/Air/Pyro Mage and Nightblade (You may be tempted to add to the "roguish" character the traditional skills used to solve some challenges... I assume you have already the knowledge to avoid that extra pitfall. Just focus on trying a 2 stats character with a weapon skill)... If possible let another real person play the Mage and see what happens at resolving conflicts (not just combat) during the game (Specially if he gets Invisibility)... You don't need to even play the entire game, just try to finish Cysae, and if you manage do take a note on the different party "tactics" you both had developed.
It's the standard check about balance... Compare the winning combo versus the weakest and see the difference in performance (The real weakest would be a pure Rogue loaded with Dirty Deeds skills... But that would make comparisson harder as it will mix a Combat oriented 3 skills character with an, in theory, "usefull" characer for OOC situations).
The only real conclusive evidence a look at each attribute, and skillset that it relates to, brings, is that it shows us which combinations of stats are stronger and which are less stronger. But it does not mean that it is unbalanced or that it even shows us where imbalances exist.
This phrase is selfcontradictory... How can be a stat + skillset "stronger" than other and not be "unbalanced"?
If you wanted to find a true balance, you'd have to look at each encounter in the game, specify what level the player chars have at that point, what skills, items available etc.
I just think a lot of ppl posting about balance simply come to defend their gamestyle and haven't bothered to play the game multiple times with different combinations... Which is paradoxical as they are likely playing solo, a field D:OS have no problems with as, I repeat again, offers enough gameplay elements to keep interesting each "class", meaning whatever change done to classes would not affect them as they don't have anything to compare with... For them the difference between finishing "conflicts" in 1 turn or 10 will just have an impact on game longetivity.
Meanwhile, in multiplayer, "conflict solving" is performed far more efficiently by characters able to manipulate the battlefield at distance using skillsets that require the minimum investment in skillpoints/stats to scale up to the game content... That means ultimately that one person will spend time waiting for the other or the other will be superflous in the outcome of conflicts.