Welcome to the forum.
Maybe you need help with the vocabulary of polyamory. We have one here.
The way an experienced polyamorous person might speak about what you seek is this: I am a guy seeking a poly bisexual female couple who are looking for a male partner to form an FFM V or triad.
A V is a configuration where the "hinge" (one member of the group) is involved sexually/romantically with two other people, but those two other people are not involved in that way with each other. In your case, maybe you'd be sexually/romantically involved with one of the women, but not with the other. The woman involved with both of you would be called the "hinge," and the other two the "arms" of the V. This kind of arrangement is very common in polyamory. You would be in a romantic relationship with one of the women. The other woman would be your friend, or maybe just an acquaintance. You might not click at all with each other and prefer to avoid interacting.
A triad (aka a throuple) is much more rare. In that case, all three players are pretty much equally attracted to each other, and get along with each other as partners. It's unusual for all three people to be balanced in this way. Almost always, there is a lack of attraction/long-term compatibility between any two members of one of the "dyads" of the "triad." Maybe one of the women in your imagined scenario would be a lesbian and have no sexual interest in you at all.
Say the women are named Jane and Ann. The dyads or pairs would be:
Ann+Jane
You+Ann
You+Jane
Then, all three of you together
Each dyad of a triad needs its own space to be nurtured and to grow. This would require one-on-one time for dates and sex. You wouldn't all always be available for quality time and group sex. People have lives, jobs, hobbies, do child care or elder care, get sick, travel for work, etc. All three of you would need to be able to know the other two were involved in one-on-one time when you weren't available, or not in the mood, etc.
Also, maybe Jane and Ann live together. As the newer partner (of one or both of them), you wouldn't be moving in right away, of course. If the relationship lasts, you'd be the "odd man out" for at least a year, if not two. In fact, if you were only dating one of them, the other one might not want you to move in, ever.
Are you imagining that you're going to step into a relationship consisting of two bisexual women who are sexually/romantically involved with each other, as committed life partners, who will both somehow fall in love with you, and you will somehow fall in love with both of them? Sometimes there is a threeway attraction, but it ends up fading between two of the players. What happens then? Do you continue to date one of them while the other one is displeased with you? Do you have to break up with the one you like? Some poly couples who want to "share a third" have "veto power" if a person they are attempting to share doesn't end up pleasing one of them.
A FMF sexual threesome is the most common male fantasy. There is so so so much porn where a guy is being happily serviced by two women who take turns pleasuring him orally or vaginally. In real life, having this arrangement work out for more than a quick hook-up or two rarely happens. Taking turns during sex can feel frustrating or boring. Most people prefer the intensity of the one-on-one connection, where the engagement is entirely mutual and continuous.
. I myself would want to be a part of women couples, because I feel they could complement the relationship greatly. I'm a wonderful fit in a partnership because I'm trustworthy and communicate well, and I feel it's very important for a successful poly couple.
You wouldn't be a "part of women couples." The women are the couple. You'd be a guy in a relationship with a woman, or two women, who were a poly couple.
