They equate 1000 hours to 10,000 hours (roughly) for fire engines- they have both an hour meter and odometer.
Hydraulic fluid is fine to the 400 hour mark- no need to change it sooner.
Some will change engine oil once a year regardless of hours. Oil analysis doesn’t typically support this practice- it would be moisture more than anything with that little time on the oil. But yearly or based on hours is fine.
I personally follow the manual on hydraulic and engine oil. In this day and age fluids last a long time. No need to fret- your tractor will be fine.
I do however, wash it and crawl around on and under it a few times of year to look for anything out of place. A loss bolt or a hose that is rubbing is an easy fix. In that regard an ounce of prevention is still very much worth the effort.