Just my opinion but if you are making knives to sell them, especially if you are doing runs of a particular design, then I think it's a good idea to name them, even if its as simple as "Model 23." I think this helps people who have followed your work differentiate between the different designs and options that you provide. I also think that the name can play a role adding to the "attractiveness" of the knife. I know a lot of people would disagree with me here but take JT's 2nd Amendment Knife (JT, I hope you're okay with me using this as an example), to me it would sound like JT designed this knife with a purpose in mind and the name was a culmination of his thought process. I really like the name he picked and it does, I think, increase my personal opinion of the knife. Granted, I could be totally off my rocker thinking this, I'm just saying...
So, without the rambling, if you're doing individual custom knives I don't see a need to name them beyond your personal preference. If you are making knives and selling them, especially if you are doing runs of a particular design, then I think a name is more than appropriate.
Clear as mud.