I suggest that instead of having separate "Characters" as login names, there instead be the option for the SAME character to exist as a series of "Classes".
Here's an example to illustrate my poorly worded suggestion to clear up some ambiguity.
I'm playing a character called "TomRaper_of_PBR". I like playing strength build Polearms, but I also enjoy Archery. Instead of having "TomRaper_of_PBR" and "TomRaperArcher_of_PBR", consolidate these two "characters" into one character of two classes. Instead of logging out, changing from TomRaper to TomRaperArcher, and logging back in you can just change classes in the "Choose Class" menu.
You can therefore switch from one kind of character to another without leaving the server and using the name that everyone identifies you with.
Although I'm an enthusiastic supporter of getting rid of the arbitrary "Main/Alt" distinction, I believe it could still be preserved if necessary.
You would level both characters separately still, ideally. Although if you just built them differently, I'd be totally down with that too.
If necessary, have the player's multiplier reset between builds to prevent any sort of abuses- cheaper speedbuilds switching to expensive-gear strength builds for example.
This has some collateral benefits as well- people can just use their normal names without resorting to TomRaperArcher or other such frivolous names.
Also, the "But this is cRPG, we don't have classes!" argument holds no logical water here for the following reasons:
(1) Yes, we do. You're welcome to customize the hell out of them, but we have 6 weapon categories and a host of customization and hybridization options from there.
(2) We already have alts out the wazoo to let people do this. The suggestion simply makes using alts much more convenient.
(3) The concept of cRPG is awesome because it allows far more freedom than vanilla Warband MP. This concept only expands upon this liberation from the restrictions of Warband.
So, how about it? Let's make the game simpler and more intuitive.