the celts, of which the scots (and maybe scythians) were members, had a broad range from the steppes thru to ireland and on south to iberia, galetia in southern poland, 'gaul' in france and galetia in northern spain were all celtic. in some respects more advanced than their roman neighbors who feared them. they were not 'civilised' in the original meaning , they did not live in cities, 'civis', but had a village and tribal based confederation. the romans proceeded to demolish that, and the results were written down by the romans, not the celts, so our knowledge of them is reduced.
my maternal grandmother was an austrian galetian from somewhere between cracow and vienna. that area is one of the most fought over areas of the world, and the term 'ethnic cleansing' should have originated there. the scythians were likely celts, one of the recent 'king arthur' films used scythian archers as auxilliary troops stationed at hadrians wall as the arthurian knights and woad painted celts as their allies against the saxon (sax meaning 'sword', the 'angles' were spearmen - they eventually mingled into the anglo-saxons) invaders as rome pulled back the legions. might be closer to tha mark than we think
(i'm looking forward to the latest 'last legion' flick when i can get to see it.)