Don't know if this is any help or not.
We towed by B & my G/F's Scout over 3000 miles last summer,on my 6x12, dove tailed trailer. Last 2 ft. were dove tailed. Each bike had room enough around them to hook up a bunch of tie downs & locking cables.
I did have them in staggered wheel chocks, the B was a tad back towards CG & the Scout was a bit fwd. of the CG so we wouldn't have too much tongue weight. Neither was against the front of the trailer.
If tongue weight isn't a big deal, off set / stagger them a bit & it should be EZ. You'll have more room front to rear than we did, due to my last 2 feet being dove tailed.