UID setting on working Drupal

Trying to install PHPBB3 to one working Drupal site (5.1). I already have 38 reged users. I am not sure about this part:

Tweak Drupal's user sequence phpBB creates users for the different search engines. Their user id will overlap with users in Drupal, so we need to make sure Drupal does not overwrite them.

Use something like phpMyAdmin to look at the table „drupal_sequences“, update the row with name „drupal_users_uid“ to have id = 1000: UPDATE databasename.dru­pal_sequences SET id = ‚1000‘ WHERE drupal_sequen­ces.name = ‚drupal_users_uid‘ LIMIT 1 ;

Note: If you are starting with a database that already has users, just make sure the sequence number is set to something higher than the largest existing user id, and leave at least 50 to spare.

If I set ID to 1000, then new reged users will have 1001 ID and more and will not overlap with PHPBB users ID´s. Right?

But what with my 38 users with UID´s from 1 to 38 that overlap with PHPBB bots ID´s??

thx