MPJ is a good example of why selling the farm for Markannen would be a terrible idea.
MPJ is on an awful cap killing contract. If he wasn't on a contender then sure, maybe he'd put up bigger stats like Markannen. And as it is, he puts up fine numbers, 16-18 points a game on 40% from 3 or so these past 2 years with 6-7 rebounds.
But he's expendable and they could have spent their money better. Ultimately it's just overspending for three point shooting and spacing.
Money should be for Wemby and whoever is the on ball creator. Make everyone fit around that that. And no matter what moves they make this summer, there has to be enough money to pay for that non-wemby creator or enough assets to get him, via draft or trade, and Markannen ain't that guy.
Another example would be Towns. While he's become a great shooter at his size, he can't be counted on to generate for himself and is the most restrictive contract they have. the Wolves media guys I listen to were thrilled with Dillingham because they needed someone else to create and Towns couldn't. So a 160 pound rookie will have to carry the weight of all their dreams.
People might argue, pay Markkannen now and figure the other stuff later. Everyone's paying big, look at Boston! But No way the Holts and their minority partners are ever going to pay the kind of money that Boston has committed to, so much their owner is bowing out. They'll be 2nd apron with just the starters in a couple of years.
If a tall shooter is what the Spurs need, they could probably get Towns off the Minnesota books for a lot less next summer, same with Porter. Don't need to burn so much on Ainge's guy.