I’d wish it is simple as that, but it is not. I’ll ask you one question. The most dominant haplogroup in Croatia is I2a. Maybe the original Croatians are R1a only, that had asimilated I2a and shared their genes? Possible? In order to prove something you will need to know some historical facts in conjunction with arheology, etimogy and other relevant disciplines... These you cannot learn in 2 days, more often not even in 2 years. “Till then you talk fairy tales”.