Yes, you could be right about eastern styles in Celtic art. The concept of Celtic art is taking a hammering at present by people like Simon James who argues that the people of Britain and Ireland were never Celtic http://www.ares.u-net.com/celthome.htm
This infuriates writers like J and M. Megaw who have made the study of Celtic art their life's work. Call it what you will, the art of La Tene and Hallstatt is staggeringly beautiful and also closely resembles Art Nouveau - everything seems to go in circles.