Yep, Jems and RG's are very similar in design, some subtle differences, but essentially similar.
The
fretboard radius is identical on the Wizard necks and Jem necks, even though the necks are slimmer on the RG's (not including the Wizard II's, they are VERY similar to the JEM necks), so the string action, provided the frets are nice and level, will also be very similar.
Of course, all guitars are different, even if they are supposed to be exactly the same, wood has "personality", so your mileage may vary . . .
Mic