I have discovered a bug in creating CommandUIDefinition. You're creating both scaling atribute MaxSize and Scale. But Scale atribute is obsolete and invalid here.
Please look for example here:
"A ‘MaxSize’ definition must be supplied to the appropriate Scaling collection (i.e. ‘Ribbon.WikiPageTab.Scaling._children’ in this case), though it seems a ‘Scale’ definition is optional (e.g. if you want different controls to be used when less space is available) [Sept 2011 – in fact, ‘Scale’ is invalid here. Specify MaxSize only.]"
That's why i wasn't able to create anything into WikiPageTab or PublishTab.