1. Are you signing a declaration of trust with this director?
2. Has the director agreed they will open accounts for the companies?
3. Has the director specified what their duties will be for the companies?
If you are not signing a document in point 1 above then you may satisfy effective management and control being in Malta. In terms of a substance test for the Malta companies you would need to meet at least the following:
1. At least 50% of directors resident in Malta
2. An office must be present in Malta
3. Business decisions and board meetings take place in Malta
4. Operations must be in Malta so helps to have local invoices to prove local costs incurred.
I think you will be ok then with above points however. It's not Malta taxman you need to worry about but your home taxman if they are aggressive in nature.