It appears that the numbers are not stored properly in your address book. You will need to correct them in order for it to show the contact's name and not number. So, to answer your question, yes, you will need to edit every contact.
The difference between stupidity and genius is that genius has its limits.
When you take things for granted, the things you are granted, get taken.
Even a mosquito doesn't get a pat on the back until it starts to work.
Too many people miss the silver lining because they're expecting gold.
[BES 5.0.3 / GroupWise 2012 HP2]