I find it hard to believe Marwin is worth that much. Let's see what he does over a whole season rather than a 2 week hot stretch
He's pretty much on his career pace, he's just getting more AB's now. His versatility to play 5 positions, smarts, leadership. He's the type of super-sub you need to fill out a roster if you want to win it all. Pay the man.
From 2015-now, he's been worth about 23 million in 2.2 seasons. 24 millions probably is in the ballpark for what he will get if he continues to produce on average what he has done since 2015. I'd guess a little less, but 24 millions for 3 would not shock me.
Marwin has been worth 3.8 fWAR over his last ~1300 PA, which spans the last 4 seasons. Over 86 PA this season he's been worth 1 fWAR, which is a superstar pace. He has seen a huge jump in walk rate and power, which is hard to tell if he can sustain, but he also has an extremely low babip which could actually indicate his numbers could get even better. If he has turned some kind of corner (he has made changes to his stance/swing), and is becoming Ben Zobrist, $24M would be an absolute steal. But even if he reverts to the guy he has been over the last 3+ years, he will will be worth close to that amount, given that typical price for 1 war on the free agent market is ~$8M+.
I'd argue his WAR is depressed by the playing 1B & OF, even though that improves his real world value. I think Marwin over the last 3 years has shown he is a starting caliber player. He is a SS that has been a slightly above league average hitter. The big question is what will his value be to us as a guy who will play SS maybe 10 games a year and 2B even less.