Regardless of the Size of Your Business
You are obliged to issue your employees with their 5 core terms of employment within their first 5 days of starting a job, followed by a statement (contract) with their remaining terms within 2 months of their start date as defined by law. If you do not, then you can be taken to the Workplace Relations Commission (WRC)
Given that you have this legal obligation, you may as well make the most of it as an opportunity to ensure that your employees have clear well written terms that work for you too.