Alan your knowledge is great , but I have few coments. 1) Germans have never call themselves like that , that name is used by Romans and mean relative , because they first encounter with Germans was during conjoined attacks by Celts and Germans , and they writed" attacks by Celts and they relatives " , later that was used like a name for a Germanic nations 2)There is more reliable explanation of Sarmatian origins than that given by Herodotus( that they are descendants of Amazons and Scythians).Diodorus Siculus say that Scythians moved parts of Medians to they kingdom during they rule in Asia in VII century BC , and that Medians are called Sarmatians which means Solar Medes .And Kurds are descendants of Medians , thats why Sarmatians and Kurds both have I2a2 . 3)I2a2 is not a Slavic haplogroup , it is Saramatian . Slavs are mainly R1a and they are descendants of Scytians and nations they have conquered - Melanhleni , Neuri ,Androphage, ... I2a2 is strong in all regions where Sarmatians use to live : Ukraine ( coast of Black see -homeland of Sarmatians after they conquered Scytians , also there was some movement of Serbs in XVIII century to east Ukraine , and there is report by Byzantine patriarch Nichophorus that parts of Serbs and Croats have escaped on empty lands in today Poland and Slovakia-Bielochorbatoi around Krakow and Lendzans "those who live on empty land" , in today Ukraine and Belarus - Boiki and Rusini by Rascia one of Serbian states in Midle ages . It is interesting that higher level of I mth haplogroup in Europe is in Boiki 10% , and that haplogroup use to be 10% in Scandinavia during Midle ages but it has decreased. ), Moldavia and Romania ( also homeland of Sarmatians after they conquered Scytians , after colapse of Huns hier lives Ants whose names are Iranian- Sarmatian , also during the Hunic empire Saramatians use to live in Banat) , Sardinia ( Vandals mixed with Alans after move to Africa setled hier ,I think there is some I2 in Lybia to . Tacitus say that Vandals were Saramatian nation) ,Serbia - Croatia -Bosnia -Macedonia-Montenegro (setled by Sarmatian tribes of Serbs-Serboi-Siraci and Croats -Harauati mentioned by Pliny the Elder like Sarmatian tribes), Bulgaria ( Bulgarians could partialy been Sarmatian , and there is emperor Constantine setling of 500.000 Sarmatians in Thrace , same is the case in Greece , also around Thesaloniki was first setling place of Serbs , Albania was part of Car Dušans empire , north Albania to river Liesus was in Serbian state Dioclitia-Duklja and some sources say Serbs and Croats use to hold to Apolonia - today city of Fier) , Hungary ( Magyars brought with them parts of Yazigs , in Hunic and Avar empire Sarmatians lived in Banat , and Turks chase population of Banat diper in to Hungary, there was also Serb and Croatian setling in Hungary), Slovenia( there used to live Venets probably cousins of Vandals , also great numbers of Croats escaped there infront of Turks ),north parts of Ossetians ( others are quite simillar to surounding nations - probably has something to do with custom to rape whole conquered village,haplogroup G is conected to goath breaders and is present on every big mountin like Caucasus , also high in Alpes-Austria) , Czech republic ( Croats move on Balkans from there , in X century there was a Croatian kingdom under Slavnik family) , Mordvinia republic in Russia ( in the area around Ryazansk moved groups of Roxolani) ,Spain ( Alan and Vandal setlement , Katalonia), France ( few Alanic kingdoms) , England ( 5000 Sarmatian auxiliars - king Arthur) , Germany ( Serbs come on Balkans from river Elba-Laba , Sarland ). So all of I2a2 can be explained by Sarmatians moving - has nothing to do with Slavs . There is also theory that I2a2 is paleolitic haplogroup who setled Balkans during last glacial maximum , that makes no sence because Greeks and Albanians -old popultions have less I2a2 then Serbs and Croats-newcomers , also Mesapi population of southern Italy has no I2a2 and they are Illyrians that crossed Adriatic see. 4)Kurds have K haplogroup ,and the Serbs to around 3% in some aerias up to 7% . Also Volga Tatari - inhabitants of Mordvinia republic in Russia where setled some Roxolans has 7,99% K and 18,4% I2a2 . Think that is K*.
5) also Kurds do have more European genes than Greeks , atleast more IndoEuropean . There was comparing of HLA alels( A and B) amongs the nations of Mediteran , which shown that Greeks are geneticaly more similar to Etiopians than any other Mediteranean nation , especially nations Oromo,Fulani and Mossi. Theese do not aply on Macedonians and Creteans whose are in one group by similarity with Sardinians, Jews and Lebanons , whyle Greeks are i group with Etiopians , and third group are North Africans and West Europeans ( France , Italy , Spain , Portugal) .At the same time there is no conection between Greeks and other African nations . These similarity probably ocured due to some move of Etopians in to Greece after downfall of Nubian dinasty in Egipt , they havent enter the Crete because Minoian state was to strong . Antic Greeks use to believe that they religion and culture had come from Egipt. Dont get insulted some of my grenfathers few centuries ago meried some Greek girls so I also has some Greek blood.
My theory about haplogroup I is that it emerged in the aeria of Pamir in Tadjikistan and then gradualy moved toward the Europe . In Xingyang in China use to live nation of Yuezhi whose name is very similar to the name of Yazigi one of the Alan tribe, name Alan meen " one that live in stepes" .Today in Xingyang live Uygurs with 60% of R1a haplogroup and 33% of I haplogroup .
Name of Guti (Gutians) is also very interesting - it is similar to name of Goths , Juts(inhabited England) and Masagets and Tisagets who formed Alans - probably egzonim .