Agreeing to disagree, knowing who you're dealing with before starting, would be more of a starting point, rather than a conclusion. Clearly a Hindu and a Baha'i are unlikely to agree. Even with Vaishnavism, there are many very substantial differences, namely the acceptance or non-acceptance of Baha'u'llah.
There are many points that is great to be able to agree to disagree.
With life there are times we can not allow that stance.
Regards Tony