Well as the OP took the effort to send me my first PM on the site... lol... i will give my 2 cents on the subject of the question he asqued in the PM witch is sligthly different than the one in the actual post, he asked me to rate the impact of the players in their primes rather than his "level of play"...
Its insightful and really shows how intelligent posters can understand the peculiarities of this game (a game, btw, that is refreshing my passion with those playoffs and in a lesser extent, with the rise of my archnemessis team Real Madrid, every hero needs a nemessis! Go FCB) the impact of a player is related but not equal to his actual level of play, goes beyond it and affects several areas i will make an effort to numerate those areas for each one of those 4 players, under my not so humble opinion, cuz i just watched GoT and im pumped up!
The areas where players of that calibre impact are a lot, but i will focus on 5, offense, defense and "leadership" (the main game related ones, understanding leadership on the capability of comand others, by voice or actions, and raise them above the sum of their capabilities) and the 2 non basketball related, opponents/league and media, because greatness is also measured on how your actions impact your peers, be those who play against you, those who rule your ambit of action, and those who watch you, i hope i succeed doing this.
M.Jordan: 1- Offense, Well, its hard to add anything of value over other more acknowledged posters, he is who he is, if i used a 0-10 scale to rate him, i would use 10, yet if i used one that allowed me to be a little more acurate, a 0-100 one for example, i would set him in 95, problem with Michael is its hard to be objective and his legend is outgrowing him, his impact was tremendous, huge as a mountain, but he was still just a primary scorer in a triangle motion offense, so cannot be the end of all.
2- Defense, He was a tenacious lockdown defender who also liked to defend, he, like most of the great 2 way players, coasted mostly in that regard during regular season and upped his game tenfold in playoffs, yet again, he was a SF, so the impact of his defense was limited, yet BIG when needed against other star SG.
3- Leadership, well, he was Patton in a basketball uniform inside the lockerroom, he was so ferotious competitor and worker that anyone of the players he played with changed his mindset forever, there is nothing over that, even with a "bad" kind of leadership, he was the ultimate warrior leader.
4- Opponents/league, That's where the impact of Jordan starts to reach legend status, he just instilled fear, period. Even nowadays im sure some of his opponents still wake up sweating over a nightmare including him, there has not been any other player capable of that at that level, also, he probably was the main weight that made overall league balance to be in the east side for almost a decade (if you take out those bulls teams, i feel like the league was really balanced in power then between east and west, MJ made the scale go east).
5- Media... well it will be hard to write anything without going into the hyperbole... Wilt,Russell and Kareem put the foundations, Magic and Bird created the proper enviroment and atmosphere, but was MJ (and Stern) who made the NBA what is today, books has been writen about for people a hundred times better writing than me and a thousand better times more acknowledgeable, so any word i further say is pointless, he was the most impactful player for any sport EVER.
Shaquille O'neal: 1- Unstoppable force of nature, anything unstoppable has "some" impact on his trampling onwards, had he been able to convert freebies would have been 100 out of 100, the most impactful player on offense ever, as he was not, i will put it on 98
2- Defense, his impact went beyond of his defense awareness or skill, man is a huge mofo, athletic and occupied a lot of space, even without being a great defender he was a defensive anchor, people often disregards him in that aspect, but he was really impactful in defense without being a great defender.
3- Is goofy a leader? nah... had he impact on their teammates? YES, the attention he comanded in every aspect of the game made things easier for everyone else on his teams.
4- The rules of basketball were changed to prevent him to make the league a joke, he didnt instill fear on opponents cuz there was nothing to fear, opponents just accepted that Nature happens.
5- Probably the "luckiest" of the all time greats, and a media loved and lover, started his career before internet was other than a college nerds utility and ended it when social media was reaching his peak, and now he is a comentator(who is improving!) Big impact, yet not as big as his ass.
Lebron James. 1- Main ballhandlers and facilitators are the most impactfull players in the game, he plays that role and does it as well as anyone, and with that, he adds his body and skill, probably as the same level of impact that Shaq had when he's on his a-game, which is really astounding, but drops significantly when he is not, if he's a 98-99 player on his good days (70% of the days, he is consistent too) he's no more than a 90 when something bothers him, and thats the difference between all time greatness impact and "dang! this guy iis good!" impact.
2- Defense, i could copy here the same i wrote about Jordan, lockdown defender from 2-4 positions on most players, capable of contain also the ones who cannot lockdown, disinterested during regular season (excepting last season when he wanted to "show" he was a DPOY player, stupid egomania is part of being great sometimes) and capable of switching gears during playoffs, his impact in this regard is bigger than Jordan as he is able to defend some bigs.
3- Is a current player and is hard to grasp some of the things that come in this regard, he makes thing easier to the others, but to me... he's a poor leader, he simply does not have that in him, is not a fault per se, but my opinion is he doesnt have it.
4- well uhmmm his impact on opponents is neither the fear of Michael or the aceptance of being powerless against of Shaq, his peers know he is the best, they play against like you play against the best, and they refer as him as the best, but i doubt there is a single good player in the league who thinks before a game... man, we are facing LeBron, we cannot win... he doesnt do that. Again, not a fault, just a perception of reality.
5- The Decission, the first superstar of the new born social media, thoroughfully scrutinized... its obvioulsy a tremendous impact he has... not sure if good or bad, but absolutely sure hard to live with, he is "the choosen one" so i guess the good things outweight the bad ones.
Hakeem peak was in a time of my life where i had no access to NBA games and i saw too little of him (mostly taped games and some live ones, but just not enough) to give an educated opinion, sry, also Durant is just too early in his career stage to be considered in this topic, but i will give a small recap, 1- Can shoot over anyone, that is unique to him and Dirk and makes him really unique in impact, 90ish, 2- has real problems with guys smaller and faster and bigger and stronger, and there are no players of his body type... yet he's trying to overcome that same things that give him a huge advantage on offense to not be a liability on defense, he's not, so neutral, good job there, still much to work on. 3- Not a facilitator per se, not a leader, but still young. 4-meh... somehow a little more scary than lebron, but still... people fears more Kobe on stretches than any of those 2. 5- Is a good dull dude, he will survive well this media crazeness, its smart for mental health but again, dull.
I hope that long post doesnt bother any of you, have a nice day.