How does lowering the processor clock speed increase fps? I've never understood that.Both games used to be and still are system killers to emulate, even for the PC.
You'll need to enable 2 options to make them playable on lower end devices:-
1. Force 60FPS or less in page 3 of the graphics settings menu. This prevents the game from needlessly internally rendering thousands of FPS and reducing the speed of the game (especially the title screens). This option has the highest impact on improving the performance of the GOW games. (Note:- You can also force the game to run at just 30 FPS internally by heading to the ppsspp.ini file and changing the ForceMaxEmulatedFPS entry to 30. It still runs pretty smoothly at 30FPS)
2. Unlock CPU Clock in System Settings. Tick it, and lower it down until you get the speed you desire. You may not have to do this if your device is already sufficiently powerful. Still recommended for mobile Android devices, good values are 60 - 100 MHz.