I think soil conditions and how deep you run it are gonna play big roles.
Second, just what are you calling a cultivator? Used to be simply an implement with nothing but cultivator points on spring shanks.
things have kinda evolved. What is now called a cultivator......may have a disc gang on the front, cultivator points/shanks in the middle, possibly a spike or chain harrow in the back, and maybe followed by a cultipacker or rolling baskets. Lots of different combos and designs that that are still technically called a "cultivator"
The neighbor that farms in this area, just got a soil-perpetrator / soil finisher to go over the fields this year before planting as he ripped them with a subsoiler last year and they were pretty rough. The local deere dealer just took it in on trade. It was a 24' model and according to spec his ~140 HP 7230 4wd w/rear duals was gonna be too small. Which it is listed at just a tad less drawbar pull than your 5020. Dealer agreed to let him try it first to see if he could pull it. It worked well but certainly wouldnt want any more back there. I think it was called a turbo-till or something like that. IIRC, it had two gangs of wavy flat discs, with very little angle to the gangs (vertical tillage), then a rolling spike harrow, followed by a rolling basket/reel.
Perhaps you have a dealer nearby that would let you try a 20 or 24' of whatever "cultivator" or "finisher" you want and if it works...you're good, and if not....get a smaller one?