Licensing question user/computer

Hi All,

So i have 18 computers installed (licensed for 26) all have green ticks but only 10 of them have users and license spot taken.
Does this mean i have 8 unprotected PC's? or is the computer still protected even if no licensed user is assigned?

I ask this because i used ADSync then we decided not to as it will be a multi domain deployment so we deleted the domain users but the local accounts did not automatically recreate.
I have re ran ADSync and recreated the original local accounts in sophos central but it only shows 10 license spots taken?

Thanks,
Anthony.