M2 starts with dbl. basses and celli in octaves, so I'm wondering if they've might have been seated on opposite sides. I'm also wondering if it might not have been a bi-product of deciding NOT to issue this in sacd format, or DSD even. These days, most orchestras only use about 9 or 10 basses at most, so I would be surprised if Eschenbach chose to divide them. Also, you need lots of room for harps, 8 or 9 horns (and it's sometimes traditional to bring the offstage horns in for the very ending too), and tons of percussion equipment. Anyway, I'll have a listen.
Barry