I'm not sure how I feel about this.
Looking at the very recent history during the past offseason, Cashman (*or the Yankees generally, as it's tough to know exactly who decided what move) has failed pretty miserably.
Carlos Beltran: 3 years/$45 Million and -0.5 WAR
Brian McCann: 5 years/$85 Million and 2.3 WAR
Jacoby Ellsbury: 7 years/$153 Million and 3.6 WAR
Masahiro Tanaka: 7 years/$155 Million and 3.2 WAR
In total for 2014 this came to $75 million for 8.6 WAR. Even if you assume a win is roughly $7 million, that's about $15 million the Yankees wasted, just on this year. Now, those are long term contracts and there is time for the players to theoretically earn their money but the youngest hitter among them is 31 years old and the starting pitcher has a torn ulnar collateral ligament (UCL) and could require Tommy John surgery in the immediate or not too distant future. So, the likelihood that all of these players suddenly earn their keep, isn't necessarily a smart bet. There is also a chance that a $15m loss of value could be the best the Yankees get from their 2014 buying spree.
On the other hand, Cashman had a terrific trading deadline this season where he really used the Yankees financial strength to acquire good talent without overspending $9m per win as he did in the offseason . Dave Cameron laid out the case for Cashman's great deadline acquisitions in his "The Yankees Successful Summer of Reclamations" so I will just lead you there rather than re-has all the details. The simple point is that guys like Chase Headley, Martin Prado, Brendan McCarthy and co. were able to be productive players for the Yankees this summer, unlike the ghost of Carlos Beltran.
That's just talking about the last 12 months and Cashman has been the GM since 1998. There is a lot to consider when analyzing Cashman's track record, both good and bad. Also, the Yankees operating system might be slightly different than some other teams. Yes, they have deeper pockets than most, if not all, but Brian Cashman doesn't have as much say as some of the other teams' GMs do. It's certainly helpful when ownership is willing to spend money, but it's also problematic when there is a power struggle between the GM and people telling the old boss what to do down in Tampa. That was apparently (somewhat) aired out a few years, with Cashman given more power but let's just say Billy Bean has more say than Mr. Cashman. But yet again, Carlos Beltran three years?
A more thorough analysis of Cashman's record is necessary, especially being able to decipher, if possible, what was a Cashman move and what what wasn't. It's well known that the Yankees have struggled to develop young talent, but what is a systematic issue and what is just bad luck? Is someone like Jesus Montero a point for Cashman since he was a top five prospect, or is it a point against as his MLB track record has been piss poor. When people point to Cano as being the last solid position player the Yankees developed, can we point to Austin Jackson or Brett Gardner? Are Phil Hughes, Ian Kennedy and Joba Chamberlain evidence as to Cashman's inability to produce front line pitching or just bad luck because, well that's pitching.
The Yankees have been a contender throughout Cashman's tenure but they also enter 2015 with an injured C.C. Sabathia owed at least $48m, they owe Mark Teixeira $45m to be an average player, they owe all the salaries mentioned previously and we still haven't addressed the elephant in the room - Alex Rodriguez who plans on playing and is still owed $61m not accounting for any pay bonuses he could receive for certain HR milestones. I think we all know that resigning A-Rod to a $275m deal wasn't Cashman's idea, but he's still largely responsible for the situation the Yankees find themselves in, and unfortunately I'm still not sure if it's a good or bad idea to keep him on to get through it.