"The Wounded" seems to imply that Maxwell was at least partially right about the Cardassians being underhanded, but employed the wrong solution in taking his own initiative. However, that the Feds and the Cardassians agreed to exchange some border worlds and to establish a DMZ doesn't necessarily mean these agreements were the same as Chamberlain's attempts to gain peace by appeasing Germany. We don't have enough of a context for what went into them.
TNG and DS9 both support the notion that there were plenty of individual Cardassians who disagreed with their government's devotion to militarism, and that even guys like Damar (who early on was a vocal supporter of the alliance with the Dominion and believed it would ultimately help Cardassia) could switch sides when they realized they had accepted a position that was more disadvantage than advantage.
In the treaty that established the DMZ, human beings who left earth before the Federation was even founded had to give up their homes to the Cardassian Union in exchange for a peace treaty that the Cardassian Union that they seemed to have no intention of honoring. Even when the agreement was amended to allow those people to keep their homes under Cardassian rule, the Central Command did everything it could to chase the Federation colonists out of those territories.
To me, that's not far off from Chamberlain giving Hitler the Sudetenland in exchange for a peace treaty that hasn't worth the paper it was printed on. It makes the federation diplomats look extremely weak and ineffective when the Federation is bending over backwards to keep this treaty alive, when the Cardassian government violated it whenever they felt like it. The treaty only lasted 3 years (2370 to 2373) before another war occurred, that's how ineffective it was.
Also some Cardassians opposing their government's military policy, didn't really do anything to stop it. Clearly a lot of Cardassians did support this policy. A lot of Cardassians were very happy when they first joined the Dominion, including Damar, its only after a couple of years of being treated like second class citizens did they change their mind. Also Damar didn't seem to have a problem with Cardassian military policy during the occupation of Bajor. Some Germans disagreed with the military policy of the Nazi government, but clearly enough Germans supported it, so those who disagreed ultimately had no ability to stop it.
Ben Maxwell have been wrong in his methods, but considering the federation's dealings with the Cardassians over the next decade, he may have been right when he said the Federation is run by ineffective bureaucrats.