I feel like the whole fair/equal discussion goes a bit far in terms of trying to even the scales on everything. As seen from the other thread, "economic outpatient care" is bad. For everybody, including the recipient. And it causes a lot of resentment, to see someone getting what you worked so hard for, seemingly as a reward for laziness and poor choices.
But we're talking about funding education, and education has a few more elements involved than just cost. One is where a student gets in. My sister got into schools I didn't. There are many explanations for this but ultimately, she worked hard to get that opportunity and I'm proud of her. Another factor is choice of major/profession/ROI. If one kid shows great initiative, goal-orientedness, drive, and career planning, their argument to go to X more expensive school because it has a more hands-on curriculum, mandated internship program, high involvement in undergrad research, and better job placement statistics is probably a lot more convincing than their sibling's argument to go to Y school just because it's cool/fun/prestigious/they want to.
I went to a small tech school on a scholarship. Sister 1 went to an "Ivy-equivalent". Sister 2 went to a state school. Want to guess who was most expensive after scholarships and financial aid? Sister 2. My parents' deal is to loan us all the money at favorable (near 0%) rates with flexible repayment options, but they're still out the sum for a long time while we graduate and get established. It's still a privilege and a gift.
I don't think it's wrong to come up with minimum amounts you'll invest in each child's education so that each knows they have at least has something to work with. But if you have the means and they earn the opportunity, I don't think it's wrong to support one through an exceptional experience, like attending Harvard or MIT or Julliard (I think the renown and name recognition of a handful of such institutions really is worth it; that's my opinion/observation). Or maybe you invest in the business they want to start, or watch their baby, or let them live at home longer. Or none of those things because they're your kids and your money and you make the choices.
But really, I think the best thing you can do to prevent resentment is teach your kids to be happy for each other, to be proud of each other, to support each other's dreams and share the fruits of their labor instead of competing for your time, attention, and money like adversaries. The more you build up a sense of family unity, the harder it will be for these sorts of things to break it down.