Please try   Editor1.TemplateItemList = "[Fontname,Fontsize]";
You can update it to   Editor1.TemplateItemList = "[Fontsize,Fontname]";
You can refer to online example http://richtextbox.com/test/TemplateItemList.aspx
 
If you are using toolbar configuration file, please update button order in "\CuteSoft_Client\CuteEditor\Configuration\AutoConfigure\Default.config"
 
Regards,
Eric