Well it also supports my idea that Prussia and Lithuania would be one

regardless who eat what. As we have Lithuanian tag it is easier to use it.
Now I have another idea. We could have Prussian-Livonian Kingdom Tag (fantasy but it is gammy) Teutonic order should keep these two Tags, as TO and PL, this would make easier for TO to control lands in the third scenario and also for the third powers to grab and control those lands without fear of rebellion (especially Lithuania) if they create PL title.