Well, he's certainly ahead of them, by far, at this stage of their careers. As CP3 said, he has no limits. No matter the stats, because they're based to some extent on longevity, if he can bring championships to the Jazz and be here at least 10 years with All-NBA first team selections, then for sure.
You would have seen a different outcome if Stockton hadn't been the understudy to Ricky Green, a proven all-star at PG already, and Malone wasn't playing second fiddle to Dantley, one of the premier post players in the league and top pure scorers ever. We forget the Jazz had some decent players already at that time, just had not put the roster together to really compete yet. Take AD and Green out of the mix, put the ball in Stockton's hands from day 1 and he would have produced. He was just that kind of player. Same for Malone.
Hell Malone averaged 15 and 9 his rookie year, 22 and 10 in year 2 and freaking 28 and 12 his 3rd, his rookie year playing second fiddle to one of the premier post-scorers in the league. How would Donovan have fared with say, Hayword taking the all-star track to higher shots and points? He would have likely gotten around 14 ppg and been in discussion for all-rookie team, might have broken out, who knows?
Today that kind of output from a rookie would be viewed as top of the class. Hell it was then. He was all-rookie 1st team. Took him only 2 years to be all-nba and all-defensive team.
Stockton's per36 for his rookie year put him at 11 ppg, 10 apg and almost 3 steals. How would he have fared in control and not Rickey Green?
To say that Mitchell has far surpassed them even at this point in their careers is disingenuous if not just flat out ********, let alone to say "by far". The situations are different. The real test will be years 2-4 when Malone and Stockton both broke out to be among the very best at their position ever in the NBA (Stockton, year 4, 15 ppg, 14 apg, 3 spg, all-nba 2nd team; Malone, year 3, 28 ppg, 12 rpg, 2.4 spg, all-nba 2nd team, all defensive 2nd team.)
[interesting note, both Stock and Malone broke out in the same year, with significant jumps in both of their output from the previous year, that year was 87-88, and Malone's fi).
We forget so easily.