I know two particular stories of League of Legends coaches, and the reaction to either seems to tell a lot about a player's mindset. In either story, neither coaches are ex-pros, at least not that of LoL itself. One speaks of disharmony between the coach and players, who hold themselves to be (at least historically) their region's foremost experts of the game. The coach was hired for form's sake more than anything else—a de facto manager and coordinator of scrims, but whose opinions of the game were distrusted at best. After all, he wasn't even Diamond, much less Master or Challenger, so what was his opinion really worth?
The other coach wasn't highly-ranked either. Yet the treatment from his players, all high-level tournament names, was near-cultlike devotion. They looked to him for instruction in everything—how and when to answer press, when dealing with sponsors, when boarding planes...he wasn't their boss or their father. He was their coach. You don't question the coach.
One team's western. The other team's Asian. You can probably guess which one, and which has done better internationally.
Is there some magic secret to coaching? Something that makes them somehow better than the players that've spent years playing the game at the highest level? Probably not. It's not as if Faker's coaching OGN winners—or even Toyz with GPL or LMS leaders. Actually, the Season 2 world champions have been the only ones that've dipped their toes into coaching, and generally to lackluster results. Stanley's Hong Kong Attitude: failed. Lilballz's Midnight Sun: still rookies (though decent for what they are). Game expertise isn't the same as leadership capabilities—and even shotcallers make poor coaches, because leadership isn't the same as telling people what to do.
What is coaching, then, if not game expertise? Why aren't good players naturally good coaches?
Point of view
Technically, everybody in a lane-pusher has full and unlimited view of the map. Vision is shared among teammates, and unless you deliberately chose to lock it, the camera is generally on free movement. Yet viewpoint is incredibly subjective from player to player—mainly as a matter of priority and training. Playing midlane means minimal exposure to the head-to-head dynamics against Maokai, or how to survive one-on-two or one-on-three when cornered. And the AD carry probably isn't going to care over-much about general vision theory and strategy, except to not step into random bushes on their lonesome.
There's also the limitations of exposure. Tournament players are going to be a lot more focused on local rivals than what's happening elsewhere—there's just only so many hours in a day to focus on anything else. Similarly with matchup considerations. Ex-pros like EU LCS caster Deficio outright state that tunnel-visioning is a concern for pro players, where their direct experiences with what works occludes what's possible.
The coach covers for that. It isn't his or her job to refine mechanics to Faker-level perfection. Nobody can play the game for you (and it'd get you booted off the circuit for account-sharing anyhow). But the direct tradeoff for focused skill development is tactical and strategic overview. If anybody thinks they can dedicate 10 hours a day to practice and still have time (and mental energy) left over to concoct world-tier strategy, they're flat-out kidding themselves. Execution is never the same thing as strategy.
Yes, the coach needs to understand the general framework, limitations and capabilities of and within the game. Strategy cannot be conducted without knowing what your pieces are capable of, or that of the opposition. But it isn't the general's job to know how his soldiers swing their swords, only that they do so at the right time and place.
And it's the soldier's job to trust that the general knows where and when that is. That their coach's put in the hours (and, if necessary, hired the analysts) to crunch the numbers and learn the habits and trends of their opposing numbers. That while the players might be called upon to advise them on specific opponents and the results of field tests, the coach has final say on the overarching strategy they utilize—because while they're scrimming and solo queueing, he's the one conducting the HUMINT necessary to turn their skills into success.
Of one mind
I know a story even more appalling than the cultural clash of the first two. Of a team on the verge of making it big, beating back every Challenger to come within a shot of the topmost pro circuit of their region. A team that's trained for months—and in a fit of hubris, threw it all away. For what? For the right to stay up at 4 AM the morning of the final qualifying match? For the right to booze it up and relax just when they were on the cusp of victory?
Worse is that their so-called "life coach" let them.
The coach isn't your friend. They aren't the team's secret-keeper. They're not there to hold your hair back when you yack into the porcelain after a victory celebration. Their job is to turn a team of solo queue stars into a finely tuned engine of conquest. There's a reason why the most successful coaches have generally been older (in conventional sports, a lot older) than the people they mentor: we're conditioned, even grudgingly, to respect our elders, and to be more serious in their presence. And we're conditioned, inversely, to take less shit from those younger than ourselves.
The coach's guidance isn't just on what champions to practice, and where to drop wards according to the team's jealously guarded and maintained timing playbooks. It's also on them to define the spirit of the team—whether it be a China-like aggression, or the deliberative patience of the European teams, but always focused and driven regardless of their situation.
In many (most) cases, that requires the exact opposite of chumminess. Discipline is a pain point, especially when coordinated across an entire team. But there is simply no choice: victory has always gone to the more disciplined team, and the coach must be both enforcer and exemplar of that ideal. And their lust for victory must be shared by all under their command.
The other side
Granted, somebody's gotta watch the coach too. There's no financial endeavor without its corruption from on-high. The history of commodotized music's been of managers handing their artists, flagging from cross-continental road trips, nondescript baggies of white powder that'll "perk them up." Sports medicine goes through regular cycles of self-flagellation for its complicity in feeding athletes various performance enhancers in search of that elusive edge against the competition—and don't think that the athletes themselves don't at least suspect that the injection might not just be "vitamins," accepting with a wink and a thin veil of plausible deniability that this is just the normative approach to professional competition.
Naturally, this approach mainly favors the rich and well-off teams that can afford the doctors involved. And for esports, it begs the question how many teams and coaches are writing off a nondescriptly titled budget line that correlates to their team's purchase and consumption of Adderall or Provigil.
There's a mutualized relationship in any form of governance. The players must submit to discipline, if victory is their aim. But the meaning of their victory is altogether too easily lost. Especially in esports, whose double-digit work days leave even professional athletes appalled at how much of the players' early 20s are thrown away into the competitive grinder, burnout is a massive risk. There must be a reflected trust—not just that the coach can rely on the players to follow their stratagem, but that the coach won't waste their players' efforts in the process.
It's when that bond of mutual trust and respect is perfected that we'll see more western victories. Everything else's just details in its creation.