so they look at your area from entirely different angles and positions.
Backscatter is very sensitive to orientation of objects and surfaces, especially in agriculture.
This is why I included the reference to this topic in the first answer: Unexplained differences between different orbits
You can only compare images which are acquired from the same relative orbit. Sentinel-1 A and B have a revisit time of 6 or 12 days. Images from the same date are acquired from different relative orbits and can have large differences.
Have a look at how angle and looking direction strongly effect the backscatter of PAZ data in this example: Opportunity for scientific use of PAZ data