Hey doctorbadwolf, I really respect and admire you and your posts, so I'm sorry if I've gotten on your bad side here. I sincerely apologise!
I never intended to suggest that what you or anyone else want isn't valid, and I should have phrased my responses better and put in a bit more effort to some of them to not sound so dismissive and instead make my points clearly and concisely to the topic at hand. I was wrong to tell jmarktkdr2 to "go read
Exploring Eberron and then come back and explain to me why [their] argument was wrong." I was crabby and going through some tough things that day and it came out through my messages. I take ownership for my poor language and choices.
But in a broader sense of the topic at hand, I disagree with your arguments here, and you disagree with my arguments here, and that's all fine. It sure is lucky I'm not the arbiter of reasonable! I certainly don't want to be an arbiter of fun and reasonable and validity. I'm voicing my opinion backed up by my ideads of the game. You are doing the same. That's cool! We all love this game, that's why we're here discussing it.
I'm not telling you or anyone else bad-wrong-fun, and if you want to make a Swordmage in 5e, go right ahead! I loved the class in 4e, and I love the Arcane Gish concept.
I'm trying to answer the question of the OP - what class design space is left? I'm arguing that if -I- were adding classes to the game, I'd want to be as conservative as possible in my class design and make the concepts as broad as possible while carrying a narrative hook.
I believe your Monk-replacement design in the other thread is a great example of this mindset - that the Monk itself is too narrow of a concept (despite having a fun hook) - though it's a bit of a thought experiment of an alternate D&D that Monk doesn't exist as part of.
I believe that Swordmage itself is simultaneously too narrow and too broad of a concept, hence why I favour the implementation of Fighter and Artificer and Wizard subclasses. But go ahead and play what you want and advocate for what you want. I could see someone banning these martial Artificer and Wizard subclasses and arcane Fighter subclasses and unifying them under a single Gish class. Someone else just made a threat with an interesting mechanical concept of this. But I don't favour that from a narrative standpoint as the narrative of Arcane Fighter feels very class-matrix-griddy in the way that 4e tended to get caught up in. I think there are definitely stories of magical warriors, magic knights, etc, but I don't think they all belong under a single class heading.
Oh, and so that it's clear that I'm not just talking with doctorbadwolf about this, I'm sorry,
@jmartkdr2 - I don't know you and your posts here that well, but sincerely apologise for what I wrote to you the other day. I was wrong to do so. I was dismissive and I was flippant and I should have phrased my arguments in a more coherent, topic-focused way rather than rebutting you directly and personally.