I've played through most of the game on the current build (Lv7 party atm), and I'd say your guess is more or less correct.
I like the balance in the current version, it's much better than in the previous builds. There are reasons to invest in every stat, and it'll probably take you a while to find out how much you're comfortable with on each character.
For the first few levels, Memory is by far the most useful because you have so few skills, and getting your first key skills like Teleport, Adrenaline and Rage will make a huge difference. After that, it really depends on your build. It's always useful to have more skills, but whether it's more useful than the other stats is up to you. I find that mages tend to want a fairly large amount of skills, whereas melee work pretty well with fewer skills.
Wits is useful mostly for the initiative. There's no benefit being any more than 1 initiative above the fastest enemy though, so a just few points can make a huge difference. Enemy initiative goes up as they increase in levels, so you'll periodically want to invest in this, but it's usually not something you'll want to focus on unless you happen to be making a (non-Rage) crit build.
In addition to that, while being fast is helpful, it's actually not super necessary to go first in most fights thanks to the armor mechanics. You usually start far enough away from enemies to not be in any real danger. I've been playing with 2 mages & 2 warriors: one mage is very fast (just in case something nasty spawns near my party), one has moderate speed and both warriors are very slow. In most situations, I end up just delaying everyone's turns until all enemies have moved so I can group them up more easily. Going first is useful, but it's definitely not mandatory.
Primary stats are very strong, but only once you've invested a large amount of points in them. They start becoming more of a priority once you have enough Memory and Wits to do what you need to do.
I haven't found myself needing CON at all yet. Between good positioning, proper use of CC, the vastly improved new shields and the frequency of +HP rings, I rarely find myself losing health at all, and when I do I usually have enough HP to stay alive without any investment (or +CON gear). I imagine it will be far more important at higher difficulty levels. Right now, it's usually not necessary.
