I found .mpr (v0.5P) where all players have the same lfsw name. If some of the developers interested, contact me.

It can be done on LAN.

Or with AIs?

No, there are 10 players in .mpr, no AI. I thought only 2 players can play together on LAN with the same lfsw name but Im not sure

How many total mpr's do you have in your collection? I ask because I have thousands and maybe something wierd happens when you have too many. Something wierd happened to me where I was going through replays and deleted the same replay that was saved like 20 times or something. Real wierd. I have no idea why it just kept showing the same replay. The track was AS3 and I had AS3_10L_5F_1 and the bolded number was incremented through like 20 or something and they all played the same replay.

Not many, 66. I havent autosave ON, I save only very interesting fights or my league events.
MPR we are talking about is downloaded from net.

LAN can be very big ^_-
Any IP-network = LAN... so... There can be upto 23 guys at the server at the same time and they can be with any account name they want, even not real one, it doesn't matter.
There is no check for account name, cos master-server isn't in use there.