One other class that I think needs an overhaul is the warlock. The use of invocations (Agonizing Blast, Thirsting Blade) to "complete" their at-will attacks was a very bad choice. On the one hand, it creates a trap for novice players who don't realize how heavily warlocks depend on their at-wills. On the other hand, it opens up a lot of space for multiclass cheese.
If I were revising the warlock, I'd give them a choice of class features at 1st level: Eldritch Blast (use your action to make a ranged spell attack for 1d10+Cha) or Thirsting Blade (use your action to make a melee weapon attack using Cha; note this is not the Attack action and thus does not work with Extra Attack). Then they would get another feature at 5th or 6th level where they get to make a second attack with their "attack feature." Finally, an invocation would let you pick up the second option so you have both EB and TB; I feel that's more in the design space for invocations, which should focus on versatility and flavor rather than raw power.
As for the ranger, I'm interested to see what they come up with. Trading spell slots for a more powerful animal companion, along the lines of the necromancer, is an elegant solution that makes perfect sense.