Using the scale in the lower left, the field appears to be approx 1800' from SW to NE (ignoring the trees as obstacles, but not considering anything beyond) - that's enough to land a lightweight herk. No margin for error & you'd obviously be operating MOS/Assault.
Going from SE to NW, if there were no hedgerows or fences prior to the road, you'd have right at 3000' - more than adequate.
The J has no real advantage over the K in this case, except for when it came time to depart, then the K might struggle with a TO ground run of only 1800' feet whereas the J would likely be off by midfield!
Until the advent of the J, the Herk has always been able to land at fields it could not depart from, but with the J, it can now depart fields it cannot land at!
