Was King Nicholas of Montenegro politically ambitious for his daughters to make good matches and marry well?
At first, no.
The King (then Prince) had 9 daughters. Their "royal keeping" for unmarried daughters was very expensive for a poor state of Montenegro and they were "too valuable" to marry them off to someone who was a Montenegrin subject as, in that case, his family would "rise above others" and on the other hand, Princesses were "not too valuable" to marry someone from other royal families, as they had neither wealth nor blood ties with anyone.
As they were, at first, destined not to be married, he wanted to build the monastery just for them in an island on Skadar lake, where they would live. He often said:"Ohhh, poor me, what shall I do with all these daughters..."
But, through time, things changed. They were all sent to Russia, Smolny Institute, as protégés of the Russian Emperor to be educated there.
When his first daughter Zorka married Prince Peter, future King of Serbia, King Nicholas thought otherwise.
Once a foreign diplomat asked him: "What can you export from this poor country anyway?" to which he replied, "You underestimate my daughters."
He realized that his daughters were sought through Europe, just because they were tall, dark and had no blood ties to any royal family...This meant that by marrying them, other royal families would straighten their bloodlines ruined by huge amount intermarriages.
The best example is Princess Elena of Montenegro. Prince Vittorio Emanuele of Savoy was the son of first cousins (King Umberto and Queen Margherita were son and daughter of Savoy brothers) and because of that he was only 153cm tall. A marriage with some sickly European Princess who was also a result of intermarriage was out of question and they spotted Princess Elena of Montenegro, who was dark and 180cm tall and who would straighten the Royal bloodline, as Vittorio Emanuele's first cousin and potential heir, Duke of Aosta, was a healthy man, 193cm tall. That's why they chose an insignificant Princess who brought them back "health".
The same was with Grand Duke Peter of Russia, who was a sickly child. His parents wanted a healthy bride and they have chosen Princess Milica of Montenegro, who later became Grand Duchess of Russia. When the marriage occurred it was now her advantage that she was a Princess from an Orthodox, brotherly Slavic country, healthy, tall, dark and wasn't a product of an intermarriage.
The rest of the sisters followed. So, their disadvantage at first became their advantage at last.
