For a company front, the closest spacing you can do without Flutes and Sousaphones getting cramped is 2 steps.
Before doing this, remove the Percussion players and plant them somewhere (in a line behind the big company front most likely so that they are not drawing attention). This is because you'll run into bigger spacing problems from your Bass Drums than you ever will from the Flutes and Sousaphones.
Also before doing this, take out the auxiliary stuff (flags, rifles, etc) unless you really want to have your aux instructor throw a fit because "they are too close together." If it were me, I'd put them as a dome above the company front, assuming that you want to highlight what is being played.
You *can* take a company front to a 1-step interval if the band is large enough, meaning more than 81 of non-percussion, non-auxiliary playing members. That magic number is because the moment you add an 82nd wind instrument, you run out of spaces in the company front (81 goes from goal line to goal line with a 2-step interval).
The Second Drill Design Exhibition is below. Give it a whirl and see what you can do:viewtopic.php?f=4&t=5232