You guys might be amazed at what happens when adding a second bottom to a small and light tractor. The "tail wagging the dog" is the saying that comes to mind.
Of course, soil type, wetness, and vegetation are factors as well.
My 70HP with a 3-bottom requires a lot of front weight (bucket full of dirt) to keep it in the furrow. The plow wants to spin you out of the furrow with the sideways force of the turning action - it acts like a boat rudder.
That SHOULD NOT happen - - assuming proper set up.
The replies up to here have all been from K owners and I think those are anything from 15 % to 25% lighter than (however one compares cat 1 and 2 tractors, e.g. HP and nominal wheel sizes) other brands.