Hi there,
Firstly, I'm not going to get into the whole Dacians or no Dacians argument.
The source that is quoted discusses the Roman Republican dinar imitations from Thrace. The Balkancelts article, and the article which you quote, points out that these imitations were made not only by Dacians, but also by the Celtic tribes. It also points out that the coinage from Thrace, in particular that from today's sub-Balkan central Bulgaria, could not have been made by 'Dacians' as there were never any 'Dacians' in that area. Unless you propose that today's Bulgaria was also part of 'Dacia'?