The accepted rule of thumb is that one engine hour equals 50 miles. I follow the owners manual's service interval, 200-250 hrs on oil/filter changes or about 10,000 miles. I have two tractors that have broke the million mile mark, all on Wix filters and Delo 15w-40, the only oil I use. I highly doubt any of the JD, IH, etc oils/filters are any better. There is no A or B service schedule with tractors, just one. Diesel engines in tractors are run more like a diesel is designed to run, start it maybe twice a day and run it for several hours at time all at one rpm, not like a pickup that may get started several times a day, often never warming up with the rpms up and down all the time. I would say that a pickup is run in more horrid conditions than most tractors just because of this. Oil filtration is the same but most tractors have an much better air filtrating system with an air filter that is designed to be cleaned several times before replacing. This is done only when the clean filter light or filter minder says it's time, to do otherwise is counter productive. Most tractors have an non cleanable inner safety air filter that rarely collects anything unless a filter fails or a person gets messy while servicing. The inner filter is good for at least 10 main filter changes before replacement. Most tractor all filters also use centrifugal force to throw most of the dust away from the filter. Most tractors have screening and seals to keep the big stuff out of the air intake and coolers. Other than that most everything else is the same.
Had to use the word most a lot here because there are cheapo and homeowner type tractors out there that aren't designed as far as filtration as most gassers.