Any character can sometimes get surpassed in his normal "schtick" by another character who specifically builds towards that schtick. That's the whole point of the system... so you don't REQUIRE any one specific class.
Concur. I think that is one of the better design features of later versions of the game. I still think that Classes can be much better designed than later versions of the game to be far more individualized, and to be far more potent at what they do (as in earlier game-Class versions), versus all classes being smeared out so that everyone is everyone, or just a different version of the same thing, as in 4E.
But allowing a Ranger (and it makes perfect sense for a Frontier's Ranger to be a good thief, for instance) to become good at Thieving skills is a good design feature of the later versions of the game. It might even make sense for a Wizard, depending on where he lives or how he operates, to be a good thief (at least in some respects), or even for a Cleric to be good at church or court espionage (this borders on what the Rogue is good at), or at other Thief skills.
I personally think the real best game design answer
lies in the middle between turning everyone into slightly different versions of each other, and making everything about a class entirely proprietary,
I'm hoping with 5E being modular in design, many of these problems can be rectified in
the milieu design the DM constructs from the basic game design parameters.
Yeah, the game design will have to provide basic parameters and still be solid enough that the core concepts and fundamentals (even down to things like class) are transferable from one game to another, but also fluid enough to allow enough parameter (in this case Class) manipulation to prevent the Classes from becoming calcified, rigid, and entirely proprietary.
I'd like to see a Thief who is uniquely a Thief and easily distinguishable from any other class, and who is in fact - the most excellent Thief. There will be no doubt what he is and what he is superb at. That will be unmistakeable by how he operates.
On the other hand I'd also like to be able to see a Ranger (for instance) who can be good at thieving skills.
With a good
In-Game Training System a good Thief could teach a smart Ranger many things about disguise and in-city manhunting just as a smart Ranger could teach a good Thief many things about tracking outdoors and camouflage. It would take sacrifice and time and effort and expense but with proper training and devotion such
cross-fertilization could be helpful to both men. Just as in real life when Cops teach Soldiers good policing and investigative techniques, and Soldiers teach Cops good Special Weapon and field-deployment techniques. It wouldn't make the Ranger a different version of the Thief, nor would it make a Thief a Ranger, it would make for a better and more versatile Ranger and a better and more capable Thief.
I think that with a good
In-Game Cross-Fertilizing Training System and a
Modular Game Design Recombination System you'd be able to do both things well:
have entirely unique Classes, and yet those classes would be able to
Train and Advance each other at complimentary and other skills and capabilities.