Erzengel has been promoted to admin position few months after he started playing the game. Which wasn't the case before, admins were usually veterans (real veterans, who played since the very start). Erzengel stopped playing awhile ago. He has less than half the mileage with this mod than the likes of Oberyn, Pepe, Gravoth etc.
Erzengel banned me because he had no clue who I was, because I took six months break when he started playing. If he knew, he wouldn't believe a word Xynox said. But in the end even Xynox became admin, which is of course, fault of Fips.
In the ancient times admins were handpicked by chadz. Then cmp started working with chadz and they started voting process where community picked their favorites but in the end devs made their choice.
When Melee was announced, actually six to nine months before that, chadz completely lost interest in playing cRPG which was the main reason why he created the mod. At that time HRE server was popular DTV heaven and Fips hand picked admins there but they were only admins on that servers. Just like SeaRiders were admins on SeaRider server. HRE server used to have only HRE members as admins and among them were many fat, angry german teenagers (at that time no older than 16). Because of that Fips gave admin powers to regular players on that server, he personally liked (Patoson, Uther). Later, after M:BG early crowdfunding, Fips and his clan being major stakeholders in the project got the special role alongside the biggest single M:BG stakeholder to do the work chadz, cmp, harald, espu and meow used to do. That would be managing this community. That is the story how former HRE DTV admins became EU admins.
Connection between admin position and real money involved is ever present in online communities and this one isn't exception. Before M:BG one dude donated 500 euros to server running cost and was appointed as admin. Problem was, he was a troll like me and used to have fun with at that time much bigger community. chadz was forced to revoke his admin rights under pressure and legend says, chadz was hella mad that time. Not as mad when Panos wrote on taleworlds forum that chadz is selling loompoints for real cash. Not even mad like he was when meow betrayed my trust and said chadz that he knows something he felt he's entitled to know but didn't (and I knew, which made many people angry because they think they are of higher value like le frog Oberyn), despite the fact history shown us that he has no place in development of M:BG whatsoever just like most of us players. Paul was also super mad about it and still is very butthurt and it shows.
tl;dr Want to be cRPG admin? Find a way to contribute, don't ask on forums. Or make someone in the chain of command vouch for you.
But keep in mind, you will be admin of tiny community and that isn't worth the time spent. Being admin in 2010-2013 meant something. Now it is silly title if that is what you are after.