It could be rough hard work to break those roots, stump size, if large, probably not going to be effective, you'll need that 4000 to be weighted down to get good traction and when you hook onto one that does not shear off or break, something else might.
You will figure this out once you give it a few tries, thing is, you just don't have enough break out force with a subsoiler on a tractor like a 4000, now a single shank 4 barrel ( hydraulic cylinders ) ripper like on the back of a crawler like the size of D6-D8 size CAT or similar tractor may make short work of this task.
I think that most if not all the suggestions given on this topic over the years will speed things up to decay, burn stumps etc., takes time if you cant get em out with an excavator, backhoe, crawler etc.
I've cleared some areas at my place and have plowed same for food plots, one area the power company cleared, I'd have preferred it left as it was but you know how that goes. This area had lots of 4"-6" diameter hard wood stumps, and let me tell you, hook onto one of those with a non trip back plow and same size tractor, will stop you and stall the tractor. I've got a subsoiler, recently aquired N.O.S. Ford, nice find, never been used and well built, I cannot imagine even attempting to use it for this kind of work after remembering what happened with the non trip back 2 bottom. Must have been '02 when they cleared this, and the last of those stumps just came out, most came out within the last few years, say 4-5 years without any aid to make em decay, that was enough time where you might win the battle to pull em out like with a subsoiler or similar, certainly not when fresh though.
I just plowed a swath on the edge of an old field, shooting lane for me, and I've mowed this are since '02, was brush and briars, been just kind of sod bound since, and don't you know it there were some roots crossing through to the woods on either side, stopped the tractor a few times, and sheared a grade bolt in my single bottom ford series 110 plow, I was thinking this area I should have used the subsoiler 1st, the plow broke up some of these roots, but boy were the in there but good, I thought I hooked onto the transatlantic phone line or something LOL
!!!