As I do not want to threadcrap I would just point out that there are any number of ways that people like to play roleplaying games & ENworld has a strong policy of not allowing people to crap on any of them. Even if it does allow off topic rambles.
Sometimes people on the internet can be the most thin-skinned, prissy little crybabies ever can't they. Is it not possible to disagree, even on a fundamental level; show passion and speak with confidence about hobbies you've done for years... but still end the conversation without being butthurt little babies. Unless we're actually roleplaying in the same game our opinions are nothing more than that, some other blokes opinion. Now as we're on a roleplaying forum I presumed sharing your opinions and ideas about roleplaying was expected, I also assumed the population of this forum was furnished with a decent enough intellect that saying "in my opinion" in every bloody post might come off as rather redundant. Was I wrong?
As people seem to get very uppity here about any deviation, I'll get back to the topic at hand.
On topic I would avoid giving defensive boosts to twf as then it just becomes a clunky way of being the same AC and damage as a shield user.
Just adding a second attack to rangers & fighters as part of the TWF style or as 11th level class features would be OK in my maths, assuming the GWF uses Great Weapon Master feat. As this feat is seen as being close to broken that might not be a suitable solution for everyone though.
Rogues could also get the benefit in which case you would want to add it to the lacklustre duel wielder feat though I think it should really appear at 11th class level for fighters & rangers not 11th character level.
Rogues get decent value from TWF anyway as it is essentially a reroll to try to proc their sneak attack if they miss with their main hand. They do have a lot of uses for their bonus action though so it's not overwhelmingly good - the new UA swashbuckler addresses this.
I will say that none of the maths includes magic weapons which while not mandatory are pretty common in D&D & one of those that adds +d6 damage would skew twf to being far better (well 2 of them ...)
This is an extremely mechanics focused way of looking at things, your use of the word "proc" for, activating you power says everything... you're basically playing this game like a tabletop MMO. I don't go out there to get more opportunities to "proc sneak attack"; because this isn't a video game and if I wanted a miniatures tactics game I'd still be playing 4th.
For me the question of two weapon combat is all about whether it makes sense in the setting and game. Now sure you can do it, but I believe you should get no combat bonus at all, because in reality, you don't actually get any advantage in combat from dual weilding. You certainly don't attack faster or more often.
Your smug quoting at the beginning of the post means nothing, and parading your stupidity around and giving e-winks to the other posters won't make you win this argument; so either grow up and discuss the subject properly, or agree to disagree and move on. You're crap at mockery via the internet and as I've never met you or spoken to you before, I've yet to develop any respect for you bar basic human courtesy, so I'll think nothing of eviscerating your childish nonsense publicly... just... like... this.
Humanoid physiology is well established in the game, we have the same shape; arms, legs, torso etc. in the same place, and have the same weapons... swords, bows, axes etc. as a late-medieval Earth society. Buildings though, could be vastly different. In a world where races don't have the same biology; for example Elves don't sleep, are bedrooms the norm? Will houses in Elven towns instead have a meditation room for trancing or will they just trance in the same room the lounge in? With no electricity, but access to magic that can and does do many of the things we use electricity for; would we see magic being used for utility in most peoples homes, especially the upper classes. There's a feat to give basic low level spellcasting, and most classes have access to cantrips at will by 3rd level, even rogue and fighter. So it's reasonable to assume at least 1 in 5 people can do cantrips. So would houses accomodate such things? Would you lack a washboard and mangle because "no-one washes clothes by hand anymore, you just go to the mages guild and pay the apprenticeship 2 silver and they prestidigitate the dirt away, for 3 silver they cast mending to fix any torn or damaged clothes"... do you see my point.
Our anatomy is decided. We know the limits of the humanoid body and understand melee fighting, Architecture though, that's different. We don't know how much the fantasy elements to this world have changed the way we build buildings so; yes, my statements are both fair and not even slightly contradictory.
Still confused? Would you like to post more daft smiles and smirk like a child? Or perhaps we can agree that we each think about this differently.
You want to primarily consider mechanics, I'm primarily considering game feel. These approaches are both fine.
I did also say in my opening post on this thread that I felt the additional attacks from two weapon fighting slowed and bogged down the game, with too many dice being rolled. One of the primary goals of 5e after all was to keep things fast and flowing, which they've achieved very well I might add. So my opinion wasn't just from a game feel perspective, but a practical one too.
Now if you want to discuss this like adults cool, if you'd rather just leave it and agree to disagree, that's also cool; but don't treat me like your figure of fun just because I'm relatively new here as a regular poster. If you really don't like me and can't bare to be exposed to opinions outside of your echo chamber, well there is an ignore button if you really can't handle having a discussion on a discussion board.