Ideally yes, you would create a separate account for each moodle so that one Moodle site can't access a model from another Moodle site accidentally or maliciously.
but.... practically the models are uniquely identified based on the site url so you shouldn't hit any collisions - here's the relevant part in the code that it uses to identify a model:
https://github.com/moodle/moodle/blob/master/analytics/classes/model.php#L1557
but.... practically the models are uniquely identified based on the site url so you shouldn't hit any collisions - here's the relevant part in the code that it uses to identify a model:
https://github.com/moodle/moodle/blob/master/analytics/classes/model.php#L1557