Originally Posted by
Cobblemaniac
Basically what nonsensei said.
To over-generalise, Shingen hits faster, Hercules hits harder. Therefore, with the best setup with wind has currently, it's more geared towards the classically named chaingun burst build, so Shingen makes more sense there. If I'm not mistaken, light will eventually reach that state as well with the introduction of the new himes up to Metatron awakening.
What I'd like to call the rocket launcher builds lie within elements like fire, where Hercules works better simply because the dmg output compares better than if you were to run Shingen, and besides E frame 25% def break.
As for Morgan shenanigans... well I'd continue referring to sanahtlig for the moment since he's tinkering with those builds currently.
Edit: To answer unregistered: when in doubt go Hercules. Shingen is kinda only for those with specific setups.
To answer free2pay: Not too much slower, Hercules has a reasonably fast burst gen but the key is that outside of +30 burst on 7t cd skill 2, the rest is RNG. Shingen has a 4t cd +35 burst on skill 1, added with the burst effect of +30 burst, Shingen can sustain multiple bursts in pretty quick succession, while Hercules is fast... for a single burst, if you don't take RNG TA into account.