Looks like my interpretation jives with Mearls'. The DM has the ACo dodging vs scary foes and possibly attacking weaker ones (that seems like how a wolf would fight). Maybe he mixes it up and helps the ranger sometimes.
With the Help action you're correct, but if you tell your ACo to Help, you sacrifice your own action, so you only get an attack off every-other round by directing your ACo to help you.
I'm saying you should be able to direct the ACo to Help when you have a single attack, or when you get the Extra Attack and you and your ACo split the attacks, you should gain the benefit of advantage when you both attack the same target -- sort of like flanking for a sneak attack, but not as powerful.
I think we are mostly on the same page then, if you read the rest of my comment.
Right now, I'm thinking an easy fix might be to change the mechanic to read: "You gain a bonus action to direct your animal companion to take the Disengage, Dodge, or Help action. You may use your action to verbally command it to take the Attack or Dash action. On a turn where you do not direct your companion, it continues to perform the last command given until that is no longer possible, at which time it takes the Dodge action until directed otherwise." I think that preserves the action economy while making the companion a bit more useful than just another trained animal, and makes it more defensive. Of course, now the 7th level expansion needs tweaking since RAW it just gives Dash as a bonus ... perhaps the 7th level fix is "On any turn when you and your companion use the Attack action against the same opponent, you each gain advantage on your first attack."
Which, sadly, just lends weight to the "Why take an animal companion when you can just buy a dog for 25 gp?" crowd, since that's the same outcome.
A archetypal class feature should provide a bit more IMO than a mechanic any other character can easily access. Insufficient playtesting of this feature is my guess.
Getting an army of elementals or undead to fight is not overpowered IMO, but it's annoying to wait on that player to take his turn.