It looks like you need to learn a lot about MP still
You took one some Van provs when I was at war with him, including one that was in the middle of my provs then, blocking my movements etc. I just took it with small force, without putting any big armies nearby [like you did]. Your next moves made it quite obvious you lack RAND experience and larger scope.
Your assumption that you can grab VPs from me was a bit naive. Also getting one from BL would be quite hard. I attacked him only to block access for Jotun to his cap.
Sure, attacking Jotun would have been hard [and maybe fatal], but for some time it was quite obvious that without him being taken down [or weakened] no one else can win. So you just helped him
