europa-universalis-iv
How to benefit from personal unions? I've played as Lithunia and had union with Poland, but … as far as I understand at some point Poland will get own king and become separated again.
Is there any way to get union partner become the part of your country?
If I'm not wrong, you can get more available advisors through idea paths.
For example, the economic path opens one advisor slot :
So does the administrative one.
With the centralization bonus (from the economic path), I can choose from 4 different advisors :
And this for each type of advisor.
That should help you to get better advisors.
Perhaps it is easier for you to provoke war against Castille or whoever controls southern Iberia. You can fabricate claims to any neighbouring province, including those who are separated by a single sea province.
For example, if you control Cadiz or Granada, you should be able to fabricate a claim in Morocco, or possibly trigger a holy war casus belli.
Another option is to abandon the Morocco plans, and instead target the Azores. That way, you might be able to colonize Africa (depending on your colonial range) or make the jump to South America directly.
Best Answer
It takes half a century, but after that duration the nation leading a personal union can inherit or integrate their subject nation so long as the leading nation has more provinces than the subject country.
Inheritance can occur when a ruler dies. See the hovertip over the king in the diplomacy screen to see the probability statistic. Main influences are Diplomatic Reputation, Stability, and whether the countries share a culture group.
Another option, if the leader in the union has 190+ relations with the subordinate partner, then "Integrate" is a diplomatic process that will get the ball rolling on the integration and is similar to annexation.