eliminate the double alley behind the squeeze chute .... have been around a lot of different systems and see a lot of them, and rarely do the doubles live up to the expectations .... single file alley will perform fine for no more animals than you are talking about .... 

to go with the single file alley, bring the hinge point of the bottom bud box gate (in drawing) to the edge of the single file alley -- make that gate 14 or 15' long so it still works for your load out and your alley -- will be angled instead of square with bud box and will eliminate the dead 'corner' at the rear of the single file alley.

sorting alley 10' to 12' wide if sorting is needing.