First, let me make the distinction between what I call “disposable” and “permanent” pet classes. Simply, necros and engineers are disposable pet classes. Their pets are designed for relatively quick turnover and not much of the class’s power resides in them. In fact, they are optional. A permanent pet class like the ranger has a significant portion of classes power in them, and they should (in theory) stick around for a while.
Second, understand I love rangers. Since way back in pen and paper AD&D days, back before so many thought of them as a “pet class” – before the concept of a pet class even existed. None of this post is about putting down the ranger.
Anyway, on to the main topic – a permanent pet is inherently unbalanced. Why? Simply the AI. A significant portion (20-30%?) of the class’s effectiveness is invested in the pet. That effectiveness is under the control of the AI, unlike non-pet classes that have complete control over their effectiveness. If the AI is poor, it drags the player’s skill down. If its too good, it carries the player. Even if it is somehow perfectly matched to the player’s skill, its still carrying the player – that’s 20-30% of your effectiveness you don’t have to think about, freeing you up to focus on the remainder. This is the core of the matter.
How to get around it? Well, one way would be to give the player complete control over the pet. Make them much more like a GW1 hero. Expose the full skill bar and give movement controls to the player. In fact, with the ground targeting system, you could probably implement a pathing system (ie multiple ground targeted locations to follow) and come up with some other clever things. However, all this would require a high threshold of skill to play the class, perhaps the highest in the game. While this might a few some happy, Anet will never do this. Rangers are too popular thematically to be a high barrier to entry class.
The only other solution I see is making the ranger more like a disposable pet class. At this point, those that dearly love their pets are likely sharpening their claws. No, I’m not advocating going back to a GW1 system that totally kittened pets. But, let’s think a moment about what has really changed from GW1 to GW2?
You still only have 3 basic commands (attack, return, passive) with the addition of one player controlled pet skill. If you want your pet to be able to do anything else, you have to use up a utility slot. Gasp, just like GW1. All that GW2 has done is shifted power from your character into the pet, given you one extra button, and a pet swap. All with a pet that can only hit stationary targets and dies horribly in AoE (of which, there is a lot).
So, I think the mechanic has to change, and it not be so pet focused. Rangers are about nature, wilderness skills, and yes, some level of animal interaction. I don’t have a perfect solution, but I think looking at the Engineer toolbelt is a good inspiration – its probably one of the two most interesting class mechanics in the game (honestly, most of the mechanics are subpar). The other is ele’s attunements. I could see a combination of these two – a sort of set of pet/non-pet toolbelt-like skills which are modified by some kind of nature attunement/utility skill choices.
Eg – the type of pet is the rough equivalent of the elemental attunement, and the skills it provides on the “nature belt” are thusly modified from this and the utility skills. Wolf/canine pets would give one set, birds another, etc. And the effects would depend on whether the pet is out or not (this requires a permanent pet storage option – or at least an “empty” slot so you could switch to no-pet).
Again, that’s all rather rough, and in fact, more of an example of ways of thinking of new mechanics rather than me saying “it must be this!”.
In short – you can’t ever balance a strong pet (ie perma-pet), because the AI will either always drag you down or carry you. Anet won’t ever give full control over pets, so a new class mechanic is needed.