Hi ,
The above pictures all pretty much the same just with different shaped rooms and some added instruments. There can be differences with the live orchestra and "Movie " orchestra.
Basically though,
1st violins on the left, 2nd Violins next to them (to the right) then Violas in the middle, Cellos on the right side(opposite 1st Violins) and Basses behind them.
Behind the Strings from left to right
French Horns, Flutes,Oboes,Clarinets,bassoons, Trumpets,Trombones,Tuba.
Behind them Percussion spread left to right.
Bells, Mallets and then drums and Timpani.
In Movie writing they often move the Basses to the middle of the mix so that the "bass" is not one sided. Also you might want to angle the violas from the dead center so that they don't fight the basses if you do that.
Another possibility is to put the 1st violins on the left and the 2nd Violins on the right of the conductor and put the Violas and cellos in between them. This can bring more balance depending on what you are composing.
I also experiment with percussion positions as I find the Timps can get lost with the low end strings so I bring them a little more center too.
This is very basic and I'm sure other people will have their thoughts,
M.