What you really need for games, tons of RAM and CPU
The SGSII has 16GB internal space which can be used to store game files, it's a lot of space, the graphics heavy Modern Combat 3 only takes up 1.4GB. It also has 1GB of RAM which is a lot. When idling, you get 800mb+ free of ram. It has a really fast dual-core 1.2GHz processor, the 1.5GHz dual-core Snapdragons are not as fast as the SGSII.
That sounds like advice a tech illiterate who thinks they know things would give out.
Most newer CPUs will cover it, but it's down to the GPU a lot more now. But you do have it right with the snapdragons (current gen not A15) not being as fast as the Exynos.