It counts for literature as well as larping – although larping does have it’s own, specific requirements.
#1 Realistic names are pronounceable. I’ve read once that Frank Herbert (not a fan) knew what he was doing when he named his leading character “Paul”. You can always try with the “but my character’s culture likes long unpronouncable names” whine, but it probably won’t get you far.
#2 Realistic names are short – or have shorter versions. Call it nicknames, if you must – but historically, family names did evolve from family nicknames (or paternal lineage etc.). People have nicknames in life as well – why wouldn’t characters have them? (Even Aragorn’s mother Gilraen called him “Estel”, if I remember correctly…)
#3 Realistic names don’t always start with your favorite letter of the alphabet. Or with A or any equally heroic letter. (I’m particularly fond of S and R – too much high fantasy in my childhood days.)
#4 Realistic people remember their names. The beginning of a larp is always confusing, but if you can’t state your name matter-of-factly when you’re asked, there’s probably something wrong with the name. Take care of it.
#5 Realistic names aren’t always pretty and/or melodic. I’m sure there are even elven parents with plain bad taste. If we’re playing the game of simulating reality, why not simulate the less pretty, but more realistic parts?