I like how they all have their individual strengths.
having mCe as your coach gives your team like +30% individual improvement + unlimited access to pool of cheap, underrated players.
--best choice for financially crippled orgs and teams trying to take a chance on up-and-comers. Dude also births new top IGLs with every team he coaches
having cheT gives you a +50% buff to any preparation against other teams, +20% anti-stratting (he spends all night before the match to give his team this info)--the top choice for rosters full of veteran players and a self-sufficient IGL
having seangares gives you a +40% discipline bonus, ingraines protocol after protocol into his players, makes their gameplay strict and maximizes teamplay--an excellent choice for young/rookie rosters.