Some religious groups are not so picky as to necessarily distrust non-members of their religion. Many Christian sects get along famously irrespective of each others seeming heretical belief and multi-sectarian churches are commonplace.

There are also anecdotes of animals that seem to fit in the hunter/prey category getting along and playing together.

Suggesting that intellectual mindsets are necessary to create behaviours relies on our intellect being our ruling aspect. This does not seem true.
The intellect is never a truly objective entity and will always interact with subjective reality.

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It actually seems that immoral behaviours are generally the product of the intellect or aberrant thought.

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On reflection, it seems some arguments are based on the assumption that the intellect is the base cause for behaviour or morals.
This seems a weak point and has no necessary validity.

We all have minds, and we all seem to behave as if our minds are telling us what to do, but any awareness of sub-conscious activities highlights that much of our behaviour may be ruled by unconscious thoughts.
How to determine whether sub-conscious activities are purely intellectual seems problematic, when there is obvious proof of phsyical driven behaviours such as pain, hunger, sexual desire.