I dont know how accurate this map is, but you cant see the connection of lithuania to the baltic sea either. Btw.: The prince-bishopric of Ermland could be a vassal at the start or a releasable tag with a core on Ermland. Historically it was first a vassal of the Teutonic Order and after 1466 a vassal of Poland.
I can give another map:
or:
The maps shows how German and Polish historians imagine situation (or try to impose). The real thing is treaties:
Polish–Teutonic War:
The (First) Peace of Thorn. It was signed on 1 February 1411 in Thorn (Toruń),
The Hunger War or Famine War. Summer 1414
Treaty of Melno. It was signed on September 27, 1422
"According to the terms of the treaty, the Teutonic Knights for the first time renounced all territorial, political, and missionary claims against the Grand Duchy of Lithuania.
Samogitia was permanently ceded to Lithuania. The Prussian–Lithuanian border ran from sparsely inhabited wilderness in
Suvalkija, through the triangle north of the
Neman River, to
Nemirseta on the
Baltic Sea. Thus the Knights still controlled Neman's lower reaches and Memel (
Klaipėda), an important seaport and trade center.
Lithuania retained access to the Baltic Sea between the towns of Palanga (Polangen) and Šventoji (Heiligen Aa) – a distance of about 15 kilometres (9.3 mi). However, Lithuania failed to develop harbors in Palanga or Šventoji as there were stiff competition with the nearby established ports Memel and Libau (
Liepāja) and unfavorable natural conditions. Thus it could not be considered a real access to the sea.
For the Knights this short coastline strip was a major sacrifice as it separated the Teutonic Knights in Prussia from their branch in Livonia. The treaty is often described as a mutual Prussian–Lithuanian compromise."
Battle of Wilkomierz/Pabaiskas. Took place on September 1, 1435.
The battle reduced the power of the Livonian Order as its army was defeated, Grand Master killed, and many senior officers taken prisoner. The damage to the Livonian Order caused by the battle is often compared to the consequences that the
Battle of Grunwald (1410) had on the
Teutonic Knights. The peace treaty was signed on December 31, 1435 in
Brześć Kujawski. The Teutonic and Livonian Orders promised not to interfere with internal matters of Lithuania or Poland. Even Pope or
Holy Roman Emperor could not force the Orders to violate the treaty.
The peace did not alter borders established in the Treaty of Melno (1422).
Second Peace of Thorn of 1466. It was signed in the Hanseatic city of Thorn (Toruń) on 19 October 1466
Both sides agreed to seek confirmation from
Pope Paul II and
Holy Roman Emperor Frederick III, but the Polish side stressed (and the Teutonic side agreed) that this confirmation would not be needed for validation of the treaty. In the treaty, the Teutonic Order ceded the territories of
Pomerelia (Eastern Pomerania) with Danzig,
Kulmerland with Kulm and Thorn, the mouth of the
Vistula with Elbing and
Marienburg (Malbork), and the
Bishopric of Warmia (
Ermland) with
Allenstein (Olsztyn). The Order also acknowledged the rights of the
Polish Crown for Prussia's western half, subsequently known as Polish or
Royal Prussia.
[1] Eastern Prussia, later called
Duchy of Prussia remained with the
Teutonic Order until 1525, as a Polish fief.
That's only facts, no my personal opinion.
Any questions?