Aye...
It's a tactical aspect indeed, and the more interesting way to rack up claims/inheritances of different provinces by marrying this way... It also pads your Dynasty Prestige too if you continue to give them titles and they go out on their own trying to conquer other provinces (since a fraction of that carries over to your next ruling character, which in turn boosts your score even by a little bit)..
There are times when it can backfire... For example, I'm playing the Duchy of Bohemia and married one of my Daughters matrilineal to one of the Sons of the Duke of Bavaria. He wasn't first in line for him, but maybe like 3 or 4th or so, so that’s how I was able to get him to my court, and most importantly he had a claim on the Duchy of Bavaria which I could plan to use in the future with the off-springs he has with my Daughter... So, he had 3 Kids with my Daughter and I thought I was safe and made him a Count of Bromo (sp?), all good right?
LOL... Nope.... All 3 of the kids died around 5-10yrs old, and thinking there would be a chance that my Daughter and Son-in-law can have another kid (as they were just in their late 20s) I wasn't worried to much, so kept on playing... A few months later my son in law died suddenly (didn't say anything about assassination), and since he had no kids alive with my daughter anymore, the province past to his father instead which was naturally the Duke of Bavaria (As remember I gave the title to my Son-in-Law, not my Daughter)... And now I got one province in my lands owned by the Duke of Bavaria, and it just so happens he's now become the "Holy Roman Empire" so I guess I won't be getting back that province anytime soon...
So yea, marrying Daughters in this game is not only dangerous the usual way (since any off-springs will have Claims on your main duchies after your Daughter passes away), but also if its matrilineal it can be just dangerous as hell when it comes to "claim" aspects that can be inherited through their kids, but I guess that's what makes the game fun.