The URL slug (in this example) is largely irrelevant.
Google will rank the page that they view is the most relevant for the user. Some sites may not have ALL the Lisa Ann videos categorized under her model profile, but the search page does for example (or at least, Google thinks it does, which is all that matters for this discussion).
Some sites' "search" template is more well optimized than their "model" template. If you have a big site, it's more likely that a user will search for Lisa Ann content on your site, get site.com/search/lisa-ann/ in the URL box in their browser, then go link it on their Twitter or blog or forum or whatever - so now your well-optimized page is getting natural backlinks. This even happens when the site has auto-suggestions enabled that link directly to the model or channel from the search drop down - a lot of people just type and hit enter.
There's really no advantage to either. If you ever reach 1m+ per day, then you may want to pay attention to the user flow for things like this, especially if you work out deals directly with models for monetization or them sharing content, etc.
Until then, worry about the fundamentals. Good content + well structured site. A lot of people think they have this, almost none actually do.