Yeah I have noticed that in my games too..

What usually happens is that Aragon gets hit by France or Genoa, and Spain responds by taking Aragon and then getting thier butt kicked around..

All the while the Almos are storming Castile/Leon

65% the AI Almos win out in Spain
30% the Castile AI wins out
05% another faction wins out, usually the English

The factions NEVER, and I mean NEVER enjoy some peace, they seem to be perpetually at war...lol

as far as the Portugese, they always seem to be somebodies footnote in the annals of history...:P

Out of my games, the only unusual winner were the Eggys who had attacked the Almos from day 1.