Correct me if I’m wrong, vanity npubs are riskier than random ones, correct?

In my head, if I were to mine a key pair to find npub1tatumnxymfyez0nlmmxf287nh9cujfuetxhk9vptwcdqg0pn8pxqxasw3d for example, someone could in theory target that easier than nostr:npub1hte85nxymfyez0nlmmxf287nh9cujfuetxhk9vptwcdqg0pn8pxqxasw3d. 

Or am I far off base because of the remaining characters? Or hell, could the same argument be made for mining npubs that ARE random?

I think I may be answering my own question here with such a small portion of your vanity npub not being enough to guarantee finding that key pair. 

Help? I’m fucking stupid?