I've read secondhand that some lower level GW people (sales reps, etc.) are recommending things like setting a limit on the number of battlescrolls and wounds.
My guess is that an increasing number of future scenarios and campaigns will lay out specific restrictions along those lines. But that's just a guess, or at least hopeful (for GW's sake) wishing. Even without that, I do think that reasonable people can work together and throw down a fun game as a cooperative effort.
If I'm reading it correctly, heroes are stand alone and can't be in units.
If this is correct, then you really don't want your opponent having the option of winning the game by assassinating one of them (sudden death).
So, you're going to try to keep your model count low.
However, many units have bonus abilities if they're larger. For example: 10 goblins suck. 30 goblins are good (especially when taking the battle shock into consideration - two units shooting at the goblins and then charging them will wreck havoc).
I haven't played yet, but I presume that's where the game balance is situated.
As for the rest... well, To hit, to wound & to save is the same.
Movement is simplified (basically 360 degree charge arc).
What I've seen so far, the shooting units aren't very good at close combat, so you'll shoot an opponent with one unit and charge them with another.
Nothing wrong with that.
Spells don't seem over-powered.
Monsters have a lot of wounds, but get weaker the more they're hurt. That's actually quite a cool concept.
I think the greatest problem the game has are those Sigmarines... bloody awful.