Here's my thing with separate finances in a marriage: They just don't make sense.
I see people post about it all the time (often with problems that have crept up) and hear friends talking about the way they manage money, but I don't see how it makes sense in the long-term. Usually, when I hear about it, it's because it's causing problems where the "poorer" spouse has to hit up the "richer for $$$ and one or the other resents their partner. It's ugly.
I get that if one or the other is going to get resentful over money, it can just as easily happen when both put their money together, but honestly, it seems like it is less of a problem.
First off, legally, when you are married it's all each other's equally. What's yours is his and what's his is yours. there are lots of perks in terms of taxes, insurance and all the rest. Should you ever get divorced (depending on how long the marriage lasts) the court doesn't care. It is all each of yours together. I get each of you want to have enough mad money to do your things, and he thinks it's fair to have more money to spend on fun if he earns more, but think of it this way:
Who is going to have the higher hospital bills at the end of life? Who is going to live longer and need more of the retirement funds? If one of you needs live-in care, does the extra cost come out of that person's savings, or from the combined savings
Don't know? Who does? NO ONE!
What if one or the other ends up being unemployed a long time or becomes disabled? When one is a stay at home parent, how much allowance is appropriate? What share goes to the children's college savings, children's allowance? How much of each other's "fun" money will be spent on the partner? How do you split expenses for a big trip ... if one wants to go more than the other? Would a maid come out of your funds and a landscaper out of his? Do you track equity in a house according to who pays more to the mortgage? If you want house a and he wants house b, but house b is more expensive, does the difference come from his account?
It becomes ridiculous pretty quickly. The partner who earns less should not always be beholden to the one who makes more. I've earned almost double what my spouse has earned over our relationship. If we had a system like yours, she'd always be broke and need my help. As it stands, it's just our money ... we both know who puts most of it in the account, and we don't abuse our finances by spending more than we should (often).
Finances are rarely an issue because we talk about our needs and wants and we shape spending goals to match our incomes and outlays. I don't think she's a freeloader because she works as she works and does what she can, just like I do. If she is working part-time or unemployed, she does more around the house, if I'm unemployed, I pick up some slack around the house, etc.
I sacrifice things I want for things my family wants ... it's a big part of being in a family and having a household together.
I like your idea and think it works best for a marriage: Lump all the $$$ together, budget together, and whatever is left for hobbies/funtime/me-money split however you both feel is equitable (this is where the compromise can happen ... does he have a ridiculously expensive hobby, costly pasttime or something?)
In my household, we don't have separate budget items for "my" fun stuff and "her" fun stuff ... it's just "fun stuff" ... because the lion share is done together.
Sounds like both of you are looking to earn pretty comfortably. I really don't get why this is a thing. Frankly his protectiveness over "his" money sounds would trip some commitment warning bells ...
And what if he doesn't bring in the $90k he assumes (or you the $70k you assume). I think a lot of new grads with advanced degrees assume earning potential that simply isn't there. Unless you both have an "in" I'd bet that he leaves school earning closer to 50k and you, closer to 40k ... just something to think about.