"My ex will always pay for the 4 children as he should as their father."
But you do know that fathers don't always provide for their children financially. Two of the fathers of your children don't provide at all. So it isn't a great leap to think that your ex at some point might choose to only provide for his own children, or, indeed, none of the children. That is particularly true if you shack up with someone else at any point.
You seem to think that him refusing to provide could never happen in the future, despite it actually happening to you twice in your life so far. It makes it seem like you might be someone who doesn't learn from mistakes.
When you specified what you were looking for a man, you said that you wanted a man with a good job, likes kids and is on your wavelength.
The fact that you put good job first (which is just code for earning a fair amount of cash) suggests that you expect this man to provide a bit for you and your 4 children, otherwise it wouldn't matter to you whether if he had a good job or not.
I don't think it is wrong to want a rich partner, but equally it is not wrong for any man to reject a woman who wants a rich partner and also has 4 kids and wants more.