It's an interesting coincidence that Armorica sounds like America but I don't think it's very indicative of anything more than that - there are probably a lot of places that sound like "America". There is a Georgia in the US and a Georgia in the Caucasus with totally different etymologies. There's also an Albania in the Caucasus and Scotland was known in ancient times as Albania - and neither is etymologically related to the Balkan Albania. There's also a Galicia in Spain (with a similar root to the Gauls) and a Galicia in Poland and Ukraine (which could possibly be Celtic, but could also be of Slavic origin).