Preference Shares Vs Ordinary Shares

[Zen]

I heard that if foreigners wanna maintain control over the company they should hold their 49% shares in terms of Ordinary Shares, and let the Thais hold the 51% in terms of Preference Shares.

I would like to know if how safe is this method and what are the risks? Are there still any possibility of being "taken over" by the Thais with this kind of share holding structure?

Thank you.