Returning to the Sorcerer discussion, I think they share one major thing with Rangers in terms of disappointing people: too many levels where you don't get anything exciting; to much waiting for that level X where they will become worthwhile. Which is why I'll actually say that if anything the Shadow Sorcerer is not powerful enough at level 18. They had a long slog to the top and deserve the rewards.
Well... I don't think so... Look
At level 7. He can cast Twin Polymorph to turn 2 allies into a Giant Ape and still use Hound III Omem as bonus action.
Well, It's incredible strong... The hound also apply disadvantage against his spells and you can cast it each turn, multiples hounds...