I can think of two advantages of the wider spaced axles:
Stability. The wider spacing will enhance stability. It may not be readily noticeable, but it does, just as closely spaced tandem axles are more stable than a single axle under a trailer of the same length.
Tire chains. The day may come when you find yourself in a situation where chains are required on the trailer. With closely spaced tires, the chains on one tire can beat the heck out of the other tire (chains are usually required only on one axle).
If I ever go back to a TT, I would like to have the wide spaced axles.