The thing about tomatoes like Marmande is being a French variety it satisfies the way the French like to eat their tomatoes and that is quite soft. In general I find that all my outdoor grown beef style tomatoes are exactly the same and that is soft. My wife and I call them big softies and when we have a tomato salad it is generally with a huge big softy cut into bite sized pieces, balsamic vinegar, olive oil and basil leaves and a whole baguette... I have actually come to love my tomatoes like this. Sorry this has not answered your question but I think it is down to the tomato type.