PS3 Frame rates vs RPCS3

Since the frame rates drops are due to lack of raw power of the PS3. In theory having more powerful hardware should balance out those issues. Unless they are more concerned about accuracy than speed. If so it will even slow down on the emulator cause it is emulating the system accurately. So yes it can fix the frame rate issues though, it may not as well..
Just like how NES emulators are more about accuracy then speed. Like when too many pixels are on screen and the emulator will still make them flash cause "out of memory." It is really up to the creators what they want to do.
PCSX2 is a perfect example of speed vs accuracy. Hell some PS3 games take into account that they won't run at a desired frame rate and uses it to determine how code is executed. Sometimes simple things such as game clocks, or some games such as encounter rates. Zelda Breath of The Wild on Wii U is a good example on how arrows are tied to frame rate for their distance. so 60 FPS vs its' wanted 30 FPS makes arrows drop twice as fast. Why there is a hack for arrows on the Cemu emulator.
Drakengard 3 is just a poorly programmed game that is designed to run at a constant 30 fps I think. So it will most likely be fine at a constant frame rate.