All things being equal, a star which is otherwise identical to ours will not have a Goldilocks zone several times larger than that of our own Sun.
Two planets is reasonable. You may even be able to squeeze three into that life-sustaining sweet spot. But five is really pushing it.
However, have you considered that one or two of those habitable planets may have habitable moons?
Imagine the Moon having a slightly stronger gravity (maybe due to an alien artifact?) and being able to retain a thin, but still survivable atmosphere.
If you don't want any "magic" involved, then one of your planets can simply be bigger than the Earth, and have a significantly larger moon, with a gravitational field to match.
Of course you should also consider that it's extremely unlikely for so many Earth-like planets to exist in a single system.
Now to address your actual question:
I believe that having two Earth-like planets in a co-orbital arrangement would render both uninhabitable.
I'm no astrophysicist, so anyone with more knowledge should feel free to correct me, however it seems to me that the balance between Janus and Epimetheus is incredibly fragile, and results in the sort of interactions which would wreak havoc on planets which must support a relatively stable atmospheric, tidal, and tectonic balance.
The reason this particular interaction works is because neither body has an atmosphere to speak of, and because one moon is four times larger than the other. Numerous other factors also come into play.
However, an Earth-like planet requires a significantly more stable orbit.