I would say in a perfect world I want the 4e classes of fighter and warlord ported in but just modified to fit the edition, but I don't think that will ever happen.
in my 'could happen' I want to take the warlock chaise.
2 subclasses, 1 at 1st and 1 at 3rd.
at 1st you would pick between a cha leader type, a int leader type, a wis defender type and a Dex striker type being based loosely on the 2 warlord builds, the fighter from the PHB of 4e and the slayer from 4e.
have 6-8 at will combat exploits similar to cantrips (some combat buy at least 1 social and 1 exploration maybe 1 that is strong rp)
then you pick from a list of 'exploits' each that has a prereq level (1st, 5th, 9th, 13th, 17th) and basically scale in power like spells do (so 1st ones are equal to 1st level spells, 5th level ones are between 2nd and 3rd level spells, 9th are about like 4th level and 13th equal to about 5th level and 17th in line with about 6th level spells) each of these you learn is like learning a spell for a warlock... and 1st choice of subclass opens up some options... but you basically get 2+ 1 every other level... more or less. You get 1 at 1st level and 2 at 2nd 'exploits' that allow you to use these... they come back on a short rest (again like warlock spells) and some scale as you level others have trade off ones as you level... but that we can nail out later. at level 11 you get a 3rd use per short rest and at 17th a 4th.
starting at 2nd level you get the equivalent of invocations. Some of these will give new at will abilities some will give 1/day use an exploit to do this big thing. some are passive bonuses. In my mind this is where things like 'charm somone' or 'expertise in a skill' can sit next to a stance ability like getting extra reactions but you need concentration...
now these exploits and invocation like things all need (IMO) labels like 'mondain, extortionary, supernatural (I used those from 3e but canny, uncanny, supernatural might be better) so in theory you can play from level 1-level 11 without ever having a supernatural ability if you want.
now here is the hard part... at 3rd level you get a subclass more invocative, something like Knight, local hero, chosen blade... but they have to all interact with all the 1st level choices.
now up above I said you should be able to play from 1st - 11th without supernatural abilities... I am fine if some of what comes next says 'no only supernatural choices' but it would be great if you could make it work without that.
starting at level 11 you get super exploits these don't silio with your others that come back on a short rest, you get them from a very short list and are the equivalent to game changing high arcana (so 6th-9th level spells)
keep it as a d8 medium armor all weapon prof class... give it something like Int and Con prof for saves, and do NOT give it extra attacks as default, but let them take one of there invocation like things to get a 2nd attack.