If 5 fields change in one shot, you wouldn't get 5 emails. You would only get multiple notifications if the user saves the document between changes.

Adding a condition on template field being set wouldn't necessarily fix this issue because if the user sets another field after setting "Task Status" to "entered", your conditions would still be satisfied.

One way to fix this would be to have this workflow add a tag to the document. You can add a condition to the starting rule to check the tag is not set. That way, on the first change, the Task Status has the value you want, the tag is not set, your workflow starts and adds the tag. Subsequent changes to the document still satisfy the field conditions, but the tag condition will fail.