It's nothing to do with the amount of cores, it's probably the case that the Galaxy S3 your comparing to is just a different version to yours, different GPU's.
Maybe Gameloft did a rushed job optimizing the game for your version of the Galaxy S3, that's probably why is runs like crap.
Then again I know for a fact the Galaxy S3 can't maintain 30-45fps in some if not all the games you listed on high settings, so I question where your getting this information.
Even the Galaxy S4 can't maintain those framerates in all these games and it's massively faster than the S3, I mean Asphalt 8 30-45fps on high? really? no chance, even on my Galaxy S4 it struggles to average 30fps.
My apologies, you're right, I thought I was running Asphalt 8 on high, turns out it was on medium. I get 30-40fps on medium, but only 15-20 on high. I am getting this info from FPS Meter app, which can also show min, max, and average for the last minute.
Also for some reason, my gamepad is no longer working with Asphalt 8. I had it working before. But the tests I did on Dead Trigger 1 and 2, and SG: Deadzone, were using my gamepad. I was getting 45-60 fps on medium on DT1, and 30-45fps on high on DT1. DT2 only has low and high, and it's the same story. 45-60 on low, 30-45 on high, except for split second major dips when, for example, I explode a dozen zombies at once, then the framerate kinda fails for a bit, but the game is more than playable on high on my S3.
SG: Deadzone is difficult to test, because when a poor wifi internet connection causes in-game lag, the framerate dips too. And for some reason, SG: Deadzone's net coding causes a lot of missing ACKs over wifi, so it lags quite often. FPS Meter told me my average framerate was 26 when graphics were set to "high", but when it wasn't lagging, I was seeing framerates from 25-35, usually around 30. Very playable.
And man, it is a huge difference to go from low to high. The character models go from being like N64 characters to Xbox 360 characters. What appears to be bloom, SSAO, enhanced reflections and real shadows, and a greater number of total polygons everywhere, they all suddenly appear when graphics are set to 'high', and they all contribute to making the game look less like Quake, and more like FarCry 3. 60 fps is nice, but I'm used to playing 30-fps on my medium-spec PC. So I don't mind having a medium spec phone that I only paid $50 for
But I couldn't even get NOVA 3 running on 'low' without 15fps framerates.
edit: nevermind, it appears NOVA 3 has no graphics settings.