well if you want a set up, you put your drums in the back. then your strings can walk around and the vocals you do whatever, dude, set it up the way you want
.......Is this from left to right?
And if so is it the person or the amplifiers postion?
bass amp is usually set up on the hi-hat side of the drums so the drummer and bass player can stay on the same track. where the person is doesnt matter. where the amplifiers does

This is a basic layout of what I have used live.
Note how the amplifiers are set.
The positions for the people were only set because we were having space issues in small gigs.