That is to consider both horoscopes together.
We look into that whether their ascendants are related to each other by a conjunction, an opposition, a sextile or a trine or not.
Is there any planet conjoining an ascendant as a friendly, an elementary, a kindred or an enmity pair or not?
If they are related and the result is a friendly, an elementary or a kindred pair, it will be the best match.
If they are not related, they would less beneficial. They could be together, but with some issues.
If they are not related and also an enmity pair, it will be a hard time to be together. They would always have conflicts.
If both have a same ascendant, that will be the most congenial to each other because their Tanu-lak is the same. Their true nature should have been the same, also with their elementary zodiacs. (It might be disadvantageous.)
An obvious disadvantage is when impaired planets are transiting, they will damage both of them. When a bad incident comes, who will be the one who takes care another, or they might be separated?
If their zodiacs are in opposition, that will be secondarily congenial. Each Tanu-lak as a true nature will be different because of elementary zodiacs is not the same. (It might be advantageous.)
The advantages are similar to the first case, but with a dissimilar weight.
Therefore, ascendants are in sextile or trine should be the best because they are somewhat congenial. When they are lucky, they would be alright with unequal benefits.
But when they are unlucky, they would take a damage very differently. They could stand by each other because both them are not crippled.
After we consider their horoscopes, we then observe their lord of wealth that in which Bhava are they staying.
If the first one has a lord of Kadhumpa (wealth) sitting in Patni Bhava, it means that that party will not care much about money and assets.
He will give them all to his spouse (or business partner). I have seen it like this in every case. He did not even ask; he gave it all.
If that one met a good spouse, that was lucky for him. But if he lived with a spender, all assets would be ruined. Although all wealth was gone, he would never ask.
Both of these cases had truly happened. For a couple’s compatibility, you can acknowledge this and go to apply it. But do not take a couple’s horoscope and interpret it
whether their relationship would last. That is a prohibition for an astrologer to predict such a case.
If the husband and wife (or a couple) are separated because of us, that would be our sin.
Living comfortably when you are old, are you sure?
If a planet of spouse is in Marana, our partner will die?