It's not unbalanced in the number of tools per se, but it is unbalanced in the effectiveness of the tools.
Take for example, the defensive skill stick. Defensive skill stick is beyond useless. In real hockey, players are taught to keep their sticks on the ice and in the passing lanes to disrupt plays by the offense. In EA NHL, holding out your stick to disrupt plays doesn't do anything. You're WAY more likely to block or intercept a pass by NOT using dss. And, when you try to use dss, it causes your player to instantly slow down to an absolute crawl, meaning that you're just going to end up letting opposing players skate straight past you, effectively giving them MORE space.
Hitting? Hitting is nice at times, but I can't tell you how many times I've hit a player with an Ovi-esque bone-crushing hit only for the player to be back up on his skates and into the play BEFORE I AM. Then you consider that tiny, speedy forwards can hip check giant defensemen into next week, and the hitting component becomes a complete wash.
Poke checking suffers from the same slow down as dss, but with the added bonus of tripping players when you poke check them while they're facing you all because your player completely ignores the puck and pokes straight at their skates.
I would not, in any way, call that balanced. When defense (and goalies) have to be near perfect just to keep up with average forwards, that's not balanced. Giving one group of players a set of premium DeWalt tools while giving the other group a set from Harbor Freight's discount section is not balance.
Thank you for coming to my Ted Talk.