First of all, when analyzing the Germanic and Swedish I1, you can't discount the impact of Finnish migration to Sweden which has been considerable and part of the "Germanic I1" in Sweden is Finnish.
Second of all, you can't analyze the Finnish I1 if you don't know the history of Finland. Finnish people, as non-germanic and how they are seen now, are not only the people migrating and bringing the Finno-Ugric language but they are in fact a mix of different peoples. It's merely a game of chance that in the end the Finno-Ugric and Finnish language became dominant in the country.
The Western Finnish region of Satakunta which is almost exclusively Finnish-speaking (compared to e.g.Finland Proper) and has been so already before the annexation of Finland to Swedish kingdom and the further Swedish migrations to Finland is the region with the highest density of I1, somewhere around 50%. That percentage is significantly higher than the regions with historical migration from Sweden, like Finland proper with 35% I1. This undoubtedly shows that the core migration from Sweden did not bring I1 to Finland, and the unique subclade to Finland also tells the same story. Finns and Scandinavians have a common history long before that time.
The Finno-ugric migrations to Finland with majority n1c1, I believe, came from 2 major directions. One migration from the Baltic states to Southwest Finland (common ancestral base with the originally Finnic Balts - Estonians still today, and the others who used to be Finno-Ugric speakers) and another came via East and Russia to Eastern Finland - these are more like the Finno-Ugric peoples of Russia nowadays. Of course these 2 have a common root somewhere along the way, but they were still clearly separated at some point long before migrating to Finland.
On the other hand Finland has also had a migration of pre-germanic peoples to the Western shores of Finland. These people, best Y-DNA traces in Satakunta with I1, were akin to Germanic peoples of that time. They mixed heavily with the Finno-Ugric population and in time language shifted to Finno-Ugric as for a reason or another the Finno-Ugrics were dominant or more advanced compared to these people. The third component of people are the original people of Scandinavia and Finland, the Saami, who were on one side forced further up north and on one side mixed with the newcomers. Tavastians in south-central Finland are clearly a mix of the Finns proper / Satakunta people and Saami. Also written history confirms that these were Finns proper who had hunting areas more to the centre and north and stumbled upon the Saami living there.
So all these migrations need to be considered when analyzing the Finnish I1. Discounting Finns as completely separate from Germanics is not true, but of course the Finnish language makes it logical to associate them with only the Finno-ugric language bearers, but that is not the complete picture.