I believe what you are asking is whether women are presumed to get total/majority of custody or placement of children when going through divorce or paternity actions.
Before answering, it is important to distinguish between "custody" and "placement." These terms are commonly misunderstood. Custody refers to the power to make major decisions in a child's life. Placement refers to where the child will be physically located.
With regard to both custody and placement, the general answer to your question is "no." The statues explicitly state that a court may not consider the gender/sex of a potential custodian when making custody/placement decisions. While it varies from county to county, most county judges hold to a presumption of 50/50 placement absent facts that would lead it to stray from the presumption (the factors for this determination are outlined in chapter 767 of the Wisconsin statutes).
Custody is nearly always awarded on a 50/50 basis. The statutes explicitly state a presumption that custody should be Joint. You will need very good reason to get the court to stray from this.
I would advise you to contact a family law attorney before initiating any actions. See our firm website for more information or to arrange for a free, no-obligation consult.
I agree the statutes provide for equal placement of the child but that means different things to different courts. The court system has read that statute as being equalized not equal. So, if mother and dad do not live in the same school district (or county as a max) they are going to receive different placement periods that are not equal.
This is all dependant on the best interest of the child. The court will not allow the placement to disrupt the childs school, and freindships. Atleast most courts will not. It is really important that you find a local attorney so that you can best determine your options.
50/50 does happen, but most cases are not 50/50.