It might be, but before specific consideration of the content of the Declaration I would like to point out the rather different ecclesiastical standing of the Declaration with, say for example, the Accra Confession. So regardless of content I don’t think the Manhattan Declaration rises to the same level of institutional consideration as some of the pronouncements by mainline ecumenical institutions. As I understand it the signers of the Manhattan document do so as individuals and not as purported institutional representatives of their churches. Even if they do so as institutional representatives of para-church or other institutions of civil society, that is of a different character than specific declarations or confessions by the church as church.

I think the Accra Confession attempts to raise a specific yes/no litmus test on globalization to an article of faith, and in a way that purports to represent worldwide Reformed churches.

Here, by contrast, is how Jim Wallis and Chuck Colson characterize the level of their disagreements on various political and economic questions:

That means that when we disagree, especially when we strongly disagree, we should have robust debate but not resort to personal attack, falsely impugning others’ motives, assaulting their character, questioning their faith, or doubting their patriotism. It also means recognizing in humility that “we see but a poor reflection as in a mirror” (1 Cor. 13:12). In other words, when it comes to policies and politics, we could be wrong.
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The scriptural admonition to pray for those in political authority is more than a religious duty, it promotes good civic behavior. It is more difficult to hate someone when you are praying for them. Jesus’ commandment to love our enemies, including those with whom we politically disagree, is even more challenging and defies the ideologies of both left and right.

This is a statement that in my mind properly recognizes the character and shape of debate on prudential matters. This is a distinction that is simply not present in far too many ecumenical pronouncements.

With this distinction in mind and regardless of a question of agreement or disagreement on the particular policies or questions, it seems to me that the Manhattan Declaration embodies the kind of civil discourse Wallis and Colson are talking about, while the Accra Confession does not.