Yeah but that's not quite what I mean, I mean how did he get 4,550 fame? The only way I know of to get huge amounts of fame is to let enemy wizards keep coming back (casting Spell of Return) and then re-banishing them.
That's basically how I got my 9600 - but the problem I found was every time I banished a wizard, I'd take over that city, leaving him one less city. Yes, they're still expanding with settlers while this is happening, but eventually they simply run out of space on the map to put new cities. That's basically what forced my game to end - the enemy wizards all ran out of space!
I suppose you could try every time you banish them, raze the city instead, but I thought razing lost you fame. So how they got 10x the fame I did is a mystery to me.