drush_invoke: is intended to have other matching functions than _validate, _pre and _post?

I've an issue with a command I'm implementing, called "cli".

I run `drush cli` and when it finish it runs also `sql cli`. What hapens is that both drush_cli_cli() and drush_sql_cli() are matched in drush_invoke() and both functions are called.

I can workaround this with no problem by changing the name of the command or explicitly define a callback. So it's not really a problem for me, but I wonder if this is the spected behaviour (by design) of drush_invoke. A feature or a bug :p