No it is not necessary to play LE to play and enjoy TON... although as several folks pointed it out already the plot intertwines so it makes sense to play both and the upcoming game
if you want to understand the plot... Taking it into count that the vast majority uses this game as fap material it is absolutely unnecessary to play either of these 3 games... who are we kidding here ?!

You can use porn sites or just download the movies
Which do you need ?

If you have previous version you don't need another full build and can update your previous version with the " update only " files ( the name is a dead giveaway innit ?

) If you don't know how get information on " how to " or better yet stick to the full build !