The only right answer here is the one you are both happy with op. So you need to sit down and reach a compromise.
For us, we do a percentage, but the percentage is high, about 70 percent, and what's left is our own to spend as we please, golf, clothes, whatever. I earn more than my husband, but in the past he has earned more than me. It's never been an issue as we make sure what's in the joint account is enough to cover our living expenses and other bits and bobs , like meals out or the cinema, and neither of us is precious about who pays for what on other things, i for example tend to buy soft furnishing type things for the house out of mine, for no other reason than I want to.
The desire to retain seperate accounts has always been mine as it's always been important to me to have a level of financial independence. My husband would happily do all in tomorrow and has always had this view, and the solution we have is one we are both happy with.
As long as you have a solution that works for you both then you have no resentment. We go for a higher percentage as the joint account is then used for things like meals out etc and there is no discussion on who pays for what on joint activities.
Because of the disparity in earnings and the reason for it, I think he's being unfair. In this circumstance I'd say he puts in 550 and you put in 300 then the joint account can be used for joint social activities, birthday presents, kids clothes, whatever.