Nicole Kidman is A-list

Need to take a comprehensive look at this. The odds of having a healthy pregnancy are pretty high until age 27, then slightly decreases until the age of 35 when the risks of an unhealthy pregnancy really start to peak.Tom has divorced all his wives when they were 33. Another thing all his ex-wives had was about the same career level. All upper B-grade or supporting role actors; enough exposure to have name recognition, but not one was A-list with any power in Hollywood. Nor did any of them come from Hollywood families. None of the divorces was sloppy, all were fairly quiet with any "problems" released like a well crafted PR. Sure, they seemed messy - like a scripted drama
Tom is a narcissist and takes a pragmatic approach to marriage. It's a contracted arrangement. He probably hasn't remarried, because he's to old to be marrying women his daughters age, and women his own age are too old to safely have kids.

actually Nicole looked so towering that Kate was an improvement. She's his height but often wore heels at premieres, creating the "i'm bigger than my man" look. Not sure why Tom liked that look but he could have easily told her not to wear heels.

Oh so important.
Sometimes ya gotta wonder.

His distinctive lack of height also made them an off pair.