I suppose it does make a difference, in that if you send things to "submission editor" they will be filed under 'this month's submissions for consideration'; whereas if you send things to Joe Blow the Senior Editor, aka the guy whose name you know but whose job you don't know the details of, working in the company of whose day-to-day running you are almost entirely ignorant - if you send them to Joe Blow they get filed under 'miscellaneous irritating mail items that Joe Blow has to deal with, either by ignoring them completely or by handing them off to the submissions editor several weeks later.'
I apologise if I am doing you a disservice; if you know an editor well enough that there are regular emails, contacts and cheques going back and forth, the personal touch might get you or your friend's book looked at more promptly or critiqued more sensitively than if it had wound up on the slushpile.
But there does seem to be this fetish for names. Running the slushpile, you find yourself collecting MSs from weird remote areas of the building. I regularly had to fetch stuff from the company MD, who had nothing to do with the actual publishing of books; he just kept the accounts. I suppose he was just the one of the great mass of people Google would spit out as a company officer, none of whom gave a toss about unsolicited manuscripts. Much of that search-upchuck, in fact, related to employees who were either in employment elsewhere or doing their time in the big slushpile in the sky, but who still got more post every week than I got on my birthday (yesterday, by the way. I got a lovely sweater.)
If you are in a situation where the submission guidelines say write to 'submissions editor', IMHO, FWIW, you should only even consider writing to a named employee if you know them personally or professionally; or at the very least, if you can scrape acquaintance with them; maybe you chatted to them at a cocktail party or a tractor pull or wherever it is the bright young literati are hanging out these days. It's just good manners, and otherwise you find yourself in the position of the guy shouting "Do you know who I am?" at the bouncer.