They're highly charismatic, and therefore able to socialize really well.
Frollo 's broship with Gaston is uncanny, his amount of friends by the end is ridiculous (amongst them the once mentally scarred hikkikomori Madotsuki, cured by Frollo's friendship), he's the only person that has ever been revived by Hades just because the lord of the death wanted to do a friend a favor.
Achmed Frollo met Gwonam in the middle of a traumatic experience in which they lost everything. Despite facing such a dark panorama, Gwonam eventually had another reason to live in Achmed... he was happy again. Gwonam got to get along with Jafar and Yusuf just because Achmed introduced them to him.
Dmitri Frollo got to be so close with Stalin, to the extent that his leader treated him like an equal (they're communists after all) and they could spend a long amount of time in a russian patrol cabin. Dmitri even broke the family tradition of learning fire powers... to learn ice powers from his master and bro.
Hans Frollo has extreme loyalty towards his family and leader... refusing to harm any of the two in any circumstance, and willing to help them in almost anything. This leads him, however, to get brainwashed by his leader, and killed by his cousin's best friend.
It is worth noting that despite being the soul of the party, Frollo is also very weird, making it hard for him to fit in society and get sexually accepted by Panty.
Frollo has done nothing really, other than having fun with his family powers, specially his pyrokinesis. This fun however, served as practice to make him the most experienced at pyrokinesis in his family, and the most resistant to hot temperatures.
Achmed Frollo After losing everything to the americans, he just sat to plot schemes, eventually forgetting about his family powers. He complemented that with Jafar's powers though, who like Frollo, also has fun with them.
Dmitri Frollo grew with the family powers and proved himself a really strong russian, much to Stalin's approval. Together they fought for communism many times, and in the trajectory, Dmitri abandoned the family powers to learn from his new role model. Abandoning pyrokinesis was a big mistake, he realized, when he confronted Frollo's Bleesun, and was unaccustomed to hot temperatures.
Hans Frollo with dedication and discipline, trained to be the most powerful member in his family. He never did conduct pyrokinteic chaos for fun like Frollo though, so he isn't as accustomed to hot temperatures. The mysterious death of Hitler prompted him to do advanced scientific researches, further making him the most intelligent family member.