So... a disc harrow is what they just called a disc back when I was a kid, right? I have 42" tandem, with space for concrete blocks on it, and adjustable pitch, angle, or whatever you call it. A Brinley, I think, and yes it's just angle iron. I have never used it but I don't think it's wide enough to cover the tracks.
But hey, it's a food plot, not a cash crop.
I have an old converted horse drawn 10" single bottom plow for the Yanmar, and we just got a double bottom for the JD. I used the single a couple months a go and it worked Ok until I broke the tip on a root. My fault- I knew it was there. It's since been welded. I have to say, it made OK furrows but didn't seem to turn the soil too well because the fabricated 3 pt hitch holds it vertically. So...traditionally, one would plow, then disc a new field, and it sounds to me like the overwhelming opinion is still the same. Use the 2 bottom, though. I'll keep the single for my 1/4 acre plots.
I can also use that weight on the disc maybe. Again, the cylinder on the Yanmar 3 pt is only single acting, so no downforce can be applied that way, and the disc doesn't weigh much.
There are all kinds of Harrows: Disc Harrows, Drag Harrows, Rotary Harrows, Spike Harrows, Swamp Harrows, Offset Harrows, etc. We try to be precise with terminology here on T-B-N or the Threads deteriorate into confusion. Yes, your Brinly is a Disc Harrow. I would not weight an angle-iron Disc Harrow myself, because I would be aftraid you might pull it apart.....but that is me. Snug the nuts/bolts before discing; do not let angle-iron frame "work."
Here on T-B-N where so many, including myself, own Recreational Tractors, some go to extremes in preparing food plots so they can enjoy more seat time. That is OK. As for myself, open the soil with a Disc Harrow, seed generously, (Fifty pound sacks of Fall Deer Plot Mix are <$20 in Florida.) roll with the Cultipacker, pray for rain. (I have rock-free, sandy-loam. Nice stuff to work, zero water retention.)
No tractor comes with hydraulic down force on the three point hitch. Your rear wheels provide traction. If you had down force on the three point hitch it would raise the rear wheels, reducing traction to zero, rather than force the implement into the soil.
All three point implements rely on weight/gravity to function. In 99% of situations implement weight is your friend, so long as your tractor can pull the implement. The great invention that made tractors practical is the three point hitch. It was invented and multiple international patents issued to Anglo-Irish Harry Ferguson in the 1920's. The three point hitch transfers implement weight to the rear wheels through the two Lower Links, and to the front wheels through the Top Link, providing crucial incremental traction.
(The exceptions are
towed Disc/Offset Harrows and
towed Cultipackers which work better with all the weight on the implements, rather than the tractor, but are not for small fields because they require too much room to turn.)
Correctly adjusting a plow is a tricky proposition, nearly a lost art in these days of "no till" ag.
3,640 PLOW ADJUSTMENT LINKS:
https://www.google.com/#q=adjust+plow+site:tractorbynet.com