Alan,
As a musician, you may be told 'stand here on this mark', or 'we're going to put you here in the mix', and you kind of have to do that. BUT, on the hand, wearing the Engineer hat, you get to put the instruments wherever you want. You are the boss, and the only rules that you have to obey are the ones that you want to.
Now, having said that, there are some basic guidelines for mixing that most people follow, because you want a certain sound.
Let's talk about The Ventures, because that's where a lot of your sound is modeled after.
https://www.youtube.com/watch?v=3sJUf4NMI...=PL&index=1Notice that indeed, the drummer is behind the lead guitarist, and the rhythm guitars are off to either side. So, if you're playing a Ventures song, technically the way you set up 'Stand By Your Man' would be accurate to The Ventures sound. At least the VISUAL Sound Stage. Remember though that the outputs of drums and guitar amps are sent through a mixing board, and once in the hands of the Sound Engineer, can be panned right, left or wherever they want. In fact, I could with a console, put the left guitarist on the right, and the right guitarist on the left. I can even make them 'walk' across the stage, sonically, just by adjusting the pan of the tracks.
https://www.youtube.com/watch?v=VR1ln52_ccM&feature=PlayList&p=B3AD0A46840A5379&index=6Now, for this one, the drums appear on the hard right, and the guitarists are all left, but if you could hear it in stereo, it wouldn't be that way, because of the mixing going on in real time.
In this video of The Beatles 'Hard Days Night' you can see Ringo is back off to the right of the stage, there's a piano back on the left side of the stage, and John, Paul and George are all to the left of Ringo. Again, because it's not stereo, you won't hear that, but live, you would, and the engineer might play with the pan and volume controls to move them around.
https://www.youtube.com/watch?v=ShrdKHeAel0&feature=relatedSo, don't be constrained by what you THINK you have to do, move things around to create what you WANT to hear.
Gary