I think sylvie has mis-understood that you want.
The top x authors can be obtained from the tiki-wiki_rankings.php, it is quite an easy task to chop out this ranking list and make it into a module for left and right display.
Basically the php side needs to call the query and pass the returns into a smarty variable. Look at the .php files in /modules/*.php for examples on that side and then you'll need the tpl side to do the actual data display templates/modules/*.tpl
There are loads that could be used as a starting point, top forum posters for example.
Let me know if you have trouble.
Hope sylvie isnt developing something we already have