I would throw in some from the “social/status” category to round this out.
Leader of Men
Alpha Body Language
Transcendental Connection
And DEFINITELY “You Are Not Alone”
This ^ module is such a crazy manifester of people, i ran a custom with it in for 2 weeks and i found a new best friend who is basically like a twin in how similar of personalities we have. It’s crazy. So, I’m thinking that deep connections are the basic of sex and seduction and YANA is designed to help you find those people you’ll have a deep, once in a lifetime connection with. Combined with your custom, it’ll create an essense of connection with ALL the “members” of your harem even if you’re not trying to be monogamous with all of them.
Because your custom is so focused i don’t think you need current invoker. I would maybe remove a couple of manifestation modules… 2 is good. Normally I would say yggdrasil/jupiter, but you already have Sexual/Gorgeous manifestation, which is very focused.
If you want a harem, you’re simultaneously trying to get as many girls as possible, but that doesn’t mean they’re all equal quality. I would add intuition enhancer to know who to keep, who to let go of, how to get the harem, where to go, etc. Seems like intuition is important for this because it’s too much to handle logically, and, women have powerful intuitions themselves and can only be understood by intuition, to an extent.
And I would add Inner Gasoline because first of all, sexual energy is sexy, but second of all, it’s gonna take a lot of sexual energy to please all those ladies 
Code of Loyalty is kind of interesting because you need someone to be damn loyal to you to get them to be willing to be monogamous-ish while you’re a player. I doubt you want girls that are juggling you and 12 other guys, but even if you want that, don’t you want to be the guy they’re MOST loyal to?
And I would switch out Aura Of Craving for Hegemon… WB is basically Aura Of Craving on Steroids, so AoC is overkill in this custom… unless you really want it. I kinda feel the same about Edge Of Falling, that’s just textbook WB stuff.
Hegemon, though, is newer tech, extra charisma, very interesting, a bit aura based but also very developmental for your charisma overall. Good choice. King’s Radiance is a good choice too, it’s about “imprinting” and getting people to remember you long after you’ve left the room. It really works, I get a lot more follow up closes on sales calls when it’s in my custom. If you want them thinking about you when you’re not there, use King’s Radiance for sure.
And temptation is a really good one.
Discordia Deliverance is healing which can add more recon and more introspection to the custom instead of action and total confidence.
With NSE in play, I think all of that will get healed if you just take action on seducing and find opportunities where you would normally get jealous/insecure, and then let the sub do it’s thing. If you want to heal, which is amazing and you should, then either consider running Primal/Wanted/Khan which have a bunch of healing in them, as part of your main stack, or just do what I do and pick your favorite healing sub and only listen to it once in a blue moon when you’re ready to handle some recon that weekend, without it being a chronic addition to your stack and distraction from your action.
So maybe turn that to this…?
SSX core
WB core
Alexander’s Play
Alpha Body Language
Leader Of Men
Gorgeous Manifester
Instant Spark
Sexual Manifestation
You Are Not Alone
Transcendental Connection
The Merger of Worlds
Temptation
Inner Gasoline
Song of Joy
Potentiator
Joie de Vivre
The Wonder
Stress Displacement
King’s Radiance
Entranced
edit: generally speaking i question if you need song of joy and merger of worlds for this specifically, but they’re good modules
in a harem type situation the girl(s) doesn’t necessarily HAVE to be loyal, but yeah the “12 other guys” thing might be a problem from a purely safety point of view… health-wise I mean 
edit: the more I think about this one the better of an idea it sounds