I reckon the points thing will put a cap of some kind on summoning.
As it stands, it's horrific to face if your army can't summon - the fact that even Nagash can be dropped by standard troops (especially at range if you've got a bit of Rend) doesn't help too much, as with just a couple of turns (and droppable as he is, it ain't gonna be quick!) he can completely change the game you're currently playing.
Archaon is another BIG NASTY....but just like Nagash, he's far from unkillable - trick is to just keep hitting him - and he's actually fairly susceptible to Mortal Wounds, as he only saves those on a 5+. Nasty, for sure. But when I can statisically knock 12 of his 20 wounds off with Thundertusks in a single shooting phase, you realise that another adjustment to the long term Warhammer mindset is due.
But that's all part of why I've taken to AoS - it's a very different game to Warhammer, and presents lots of new challenges to get really good at it As I mentioned earlier, something I'm still to get my head round in terms of tactical opportunity is the freedom to retreat from combats. Yes it limits the retreating unit for your next turn, but done at the right time, as part of a plan, you could do wonders with it (effectively switching units that are in combat). Just needs more finesse to really capitalise on it than I currently possess. Fair chunk of my current bafflement was an original mis-reading of the rule. I read it as you could only retreat up to 3", when it's actually just a normal move. Clearly this is good for Cavalry, as not only can they all get up to 'feigned flight' shenanigans, but they have the movement value to properly get out of the way.
Though I'd give an example of a unit which could give Nagash or Archaon pause for thought...
The humble Empire Handgunners. Unit of 30, that hasn't moved. 3+, 3+, Rend -1. 20 hits, 14 wounds ( I always round up. Habit!), 7 wounds on either. That's quite a difference to the potential damage they can do in Warhammer. And another good reason for me to do a thread highlighting changes etc.