Answers
According to Article 17 of Law 4251/2014 regarding the issue of special purpose, resident permits can be granted to third-country nationals who are board members, shareholders, managers, legal representatives and senior executives of domestic companies and of 1314 GOVERNMENT GAZETTE (SERIES A) subsidiaries and branches of foreign companies. The foreign companies must legally pursue commercial activities in Greece, which is proven with the procurement of a copy of the Government Gazette, or a copy of the company’s articles of association, or a copy of the decision made by their company’s competent body regarding their capacity as board members or managers or legal representatives or general managers or directors.
The entry and residence of such third-country nationals who are to be active or employed in such capacity in domestic companies shall only be permitted only if the domestic company employs at least 25 employees. The above restriction does not apply to board members, shareholders, managers, legal representatives and senior executives, subsidiaries and branches of foreign companies, which operate legally in Greece.
Since your company in Greece is a branch of a foreign company, there is no restriction for a minimum number of employees.
Your employees need to have a social security number (AMKA) and to have a tax office number (AΦΜ) to be legitimate on your purpose.
They need to be Greek or EU citizens and there are no such provisions. Of course, they should not appear as fake ones.