Can 2 cousins determine who their grandparents are through a DNA test?

Let's say both cousins are related through their grandmother on their fathers' side, but neither have parents or grandparents still alive... so that rules out the possibility of getting a dna sample from them. But if 2 cousins were to take a dna test themselves, is it possible that they could determine whether or not they had the same grandfather on their fathers' side?

Can 2 cousins determine who their grandparents are through a DNA test?

Let's say both cousins are related through their grandmother on their fathers' side, but neither have parents or grandparents still alive... so that rules out the possibility of getting a dna sample from them. But if 2 cousins were to take a dna test themselves, is it possible that they could determine whether or not they had the same grandfather on their fathers' side?

Can 2 cousins determine who their grandparents are through a DNA test?

Let's say both cousins are related through their grandmother on their fathers' side, but neither have parents or grandparents still alive... so that rules out the possibility of getting a dna sample from them. But if 2 cousins were to take a dna test themselves, is it possible that they could determine whether or not they had the same grandfather on their fathers' side?
ok, I realize that, but if they had the same grandparents, wouldn't 50% of the cousin's blood be similar enough to warrant an answer?

Can 2 cousins determine through a dna test whether or not they have the same grandparents?

Let's say both cousins are related through their father's side, but neither have parents or grandparents still alive... so that rules out the possiblity of getting a dna sample from them. But if 2 cousins were to take a dna test themselves, is it possible that they could determine whether or not they had the same grandparents on their fathers' side?