With your conditions and a 25-horsepower tractor, not quite sure why you ordered loaded rear tires, weight on all the time. The main reason to load rear tires is to improve tractor traction; yet with 25-horsepower it is unlikely you will have enough power to break rear wheel traction except under unusual conditions.
~~You may have good reasons for loaded tires which you have not posted.~~
If you do not foresee needing to lift max loads with the FEL, drop your 400 pounds of TPH counterbalance.
(( 400 pounds on TPH should be ample counterbalance for max FEL lifts with air inflated rear tires. ))
I would retain the FEL. It is very useful for pushing/leveraging the tractor out of a partially bogged situation.
Mud and wet are when R1/ag tires are superior to other tires.
"Wait a couple weeks and you will not have to spend the remainder of the summer repairing ruts."
Good advice from OOSIK.