What! A TN75 can't pull 3 bottoms? Thats the problem with todays CUT's or UT's. You see those big HP #'s but ther don't mean anything because its not the power to the ground. Heck a Farmall M could pull 3 bottoms and its less than 1/2 the power. Marketing wars have moved us from reality to the biggest claims.
lets back up here a moment; it would pull it but not as good as you would have hoped. I bought that set from guy who was pulling them with a 6610 II. He pulled them fine. However, drawbar power was probably higher than the TN75. I would estimate that it weighed more as well. I had MFWD so I thought, yeah I can pull them. i did just not very well. It was also in a field that was turned every year so it wasnt hard. The 9540 pulled them through pasture that hasnt been turned in 15yrs. It also had livestock on it for the last 4-5yrs. Can you spelled compacted? It was hard. I also have good soil for planting. About 6-12 inches of top soil, followed by yellow clay. High water table so I have moisture when most dont.
Also the JD's are horrible to pull compared to others. We have a set of Ford 101, 3 bottoms that a 3000 and a 3910 would run off with in same soil that the TN could hardly pull the JD's. Different plow, different angle, different size. Same soil.
I had a good TN75 rops model and traded it for a cab model. Dumb thing. The rops model was a good tractor, or seemed to be. The cab model with every bell and whistle was a piece of crap. It consistantly had something wrong with it. Mostly electrical items, sensors, computer need to cleared of codes, etc. I was fed up bought the Kubota and like it so far. I feel it is balanced better than the TN for pulling since its a tad longer than the TN, so perhaps that is another reason it pulls better.
I pulled the plow, hit a pine stump left years ago by my granddad, and pulled a piece of it up before the bolt broke and sheared the pin. The kubota really didnt miss a beat. The TN would have thrown me against the wheel like the old 3000 would do with a two bottom set plowing fast and the plow didnt trip.
Bottom line, since were talking bottom plows, is makes are differnet, pull different, soil variations are way different even with same set ups, and so are tractors. Its kind of hard to compare unless its all the same.
I forgot one thing. We had a set of 2 bottom JD's cant remember the model number, probably 16" maybe 14" that he 3000 could not pull. Just would bog down. Way to hard on the tractor and lift arms. Traded them and another old oliver set for the Ford 101's. They are three bottoms and work really well with both of the ford tractors. JD's just pull like FWJ stated.