Clearly the Marlins will be tanking in 2018 and 2019 and maybe even 2020. However, it's a valid question whether they are tanking as a smart baseball strategy, a la the Astros, or by necessity because the owners are broke.
I thought it was a mistake when Loria agreed to the deal with the Jeter-Sherman group over Jorge Mas, a deep-pocketed Miamian with a history of philanthropy. The Jeter-Sherman group won the bidding by agreeing to take on Loria's debt. How, they are going to pay it off while the run the organization deeper into the ground is a mystery to me. What I've read about Sherman though is that he is one of those venture capitalist types. They buy distressed companies for a song (really, Sherman's group only scraped together $800 million for the Marlins plus the $400 million in assumed debt), make them profitable (usually by laying off a boatload of workforce and basically paring the company down to the bone) and then sell them for a handsome profit. If they can get rid of that debt and make the team somehow profitable, I can see them selling for a fortune. However, I don't see how they get a good TV deal or put money into scouting and player development to sufficiently take advantage of this tanking.