Tens of thousands of seed corn are raised in my area as there are seven facilities within 60 miles of my place.  A 16/30 row planter running on a 37.5' swath is a very common setup. Some operators will run the male seed at the same time if it is a one time plant and others will have a second machine running with a male/bull planter.  With GPS and electric drive/single row control it is really easy to do it all at once but some male/female splits don't allow that.  There are also 24 row planters but they have to skip a row to make the pattern work out.

Something to keep in mind is that 99% of seed corn is planted in fields that were soybeans the year before so conditions are usually optimal for high speed planting.  We ran 8.5 mph for most of ours this year and had perfect seed placement and emergence.