To me it looks like the main point is
Needs a Quad core processor of a minimum speed per core or better.
Needs 4 channel and 4 thread multi threading capability on the chip set
Needs 6 Meg ram on the CPU
Needs DirectX 11 or higher capable Grafics card/operating system
there are chipsets in the I5 and I7 that are dual core.
those may not work so well(or even at all) if the game code is actually looking for 2 or 3 cores that it can have run the game exclusivly or as a priority.
Same with the threading,
Basically if they finally decided to use a dedicated Core/thread for NPC AI behavior, and another to the world itself that may be why its trying to tell you No this chip set will not work even though its I5/I7 of a given clock speed. Trying to use brute force speed to overcome the fact that your chip set is actually a dual core with 2 channels and limmited to 2 threads may not work.
To be blunt, a chip-set from a Sub-type with a higher Model number than whats recommended will not always be automatically "Better" for whatever reason just because the model number is higher. In some cases what your looking at is a chip set intended for use in (For example) a laptop that's intended to be energy efficient or run cooler or have "Integrated Graphics Capability" (Ie without a Graphics card because it has "Intel" inside.)