I kinda like the numbers. It helps me get an idea about my fellow players a little bit, even if it's my first time meeting them. If the guy has peasant clothing and a low-tier weapon, I either ignore him or just swat him like a fly. Same attitude when he's on my side: if he has shit gear, I don't consider him a real teammate, just a funny sidekick.
However, if he has a number in his name, especially if it's higher than mine - I immediately give him the benefit of the doubt, that maybe he's not just a little shit, and he may be dangerous.
What I would really like though, is a length limit for names. I know it won't happen: clan tags, alts, people who just want long names, etc. But honestly, do you REALLY think people will remember your full name if it's 'SeaRaider_Fjord_Sverkerson_with_Longsword_cause_that's_the_shit_now'? Heck, they'll either call you SeaRaider (image if that's a clantag), MAYBE Fjord, but most likely they won't take the time to even read your annoyingly long name. OK, if you're constantly in the top 5, they might. But mostly you don't know that in advance when you register your character, so that's still not an excuse.
Your name has a main purpose: to identify you. The shorter, the better! If there's a guy whose name is 'T' for example, I'll never forget him.