I've had a fair amount of experience with snakes and I find them to be pretty honest in terms of how you read their body language and emotions. They'll tell you when they're grumpy. They'll tell you when they're okay.
But I don't think any arranger should ever write a drum part for a drummer because if a drummer can't create his own Interpretation of the chart and he plays everything that's written he becomes mechanical he has no freedom.
