IMO, the phrase world class is thrown around quite flippantly - where players only need a few months worth of performance to be classified as world class. Everyone has their own definition, but intuitively, you're not a world class player if you're not Top 3 in your position (positions where there is a deficiency of very good players are subject to an even harsher limit - like central defenders in recent years), or aren't selected to the World XI (or the 23 man squad at a stretch) with a list of
footballing parameters (and not marketing or popular appeal - which is often the norm with players of the Spanish duo in recent years) that are similar to Eric Batty's in the old World Soccer World XI lists.
Though there are tiers in that, too, especially in terms of consistency and maintaining a good mean level - some are unstable and drift in a out of the classification (so they're
not always world class - like Di María), whereas others are permanent features over several years.
Wrt. the list in the OP:
1. He is not able to bring his teammates up to another level, especially in difficult matches - this one is open to interpretation because some are more suited to certain circumstances. There are players who have solid fundamentals and play at a consistent 'world class' level in the big games, but because of their quieter innate personality, they don't necessarily bring their teammates up to another level. Leadership and aura are intangibles that aren't prerequisites for world class classification, IMO.
2. He needs other world class players around him so that he himself can perform at world class standards - this is also open to interpretation because some world class players struggle when they play with other world class players. On the other end of the spectrum - a lot of world class players played with (or play with) other world class or
just below world class level players as part of the team's framework. It isn't about needing world class players, but more of - that's the only evidence you have, and any projection would be purely hypothetical because they haven't actually evidenced a similar level in a weak team. Playing with other world class players is a double edged sword - because you might not shine in that elevated company, or alternatively - it makes things simpler in that some of the others divert the attention away from you. eg. Messi's presence creates room for Neymar. If the latter was at United, he'd be double and triple marked - thus making things subjectively harder for him.
3. He only has world class performance when he plays against small teams - easy, then the player is not world class - with very, very few exceptions.
4. If opponents are top teams with world class players, he mostly play like shit - again, not world class - with very, very few exceptions..
