Between AMD APUs and AMD CPUs, the CPUs will give you better performance.
As for AMD CPU vs Intel CPUs in games the following benchmarks from Techspot.com should help paint you a picture. Intel CPUs generally performs better than AMD CPUs especially in games that are CPU intensive. The more CPU intensive the game, the larger the performance gap.
http://www.techspot.com/features/gaming/gaming-benchmarks/
Alien Isolation is an example of a game that is not very CPU intensive so weak CPU can provide pretty good performance. Far Cry 4 and the Witcher 3 are examples of games that are dependent on the CPU, but not too much. GTA 5 is also an example of a game that is a bit CPU intensive. However, the CPU benchmarks are for 2560 x 1600...