do read and write Arabic very well.
The issue here is that among Arabs and most Muslims until recent times, there was no concept of "surnames". So we have been trying fit a square rod into a round hole.
The Arab names were always written as follows:
A, son of B, son of C, son of D, ...... This list could go on for several generations. The word in Arabic for son is "ibn". So it would be A ibn B ibn C .....
If there was a prominent ancestor, then he would be considered to be the progenitor of that clan or tribe, and his name would be written at the end with an "i" added to it. These are names like Qurayshi, Hashimi, Makhzumi, Asadi, Umawi, Abbasi, etc. Some of these names were Latinized in later centuries. Thus Umawi became Umayyad, and Abbasi became Abbasid, etc. Let explain one specific example.
The Arabs of Makkah were descended from Fihr who was also known popularly as Quraysh. So all his descendants are known as Qurayshi, or those who belong to the tribe of Quraysh. Thus Prophet Muhammad would be known as Muhammad ibn Abdullah ibn
Abdul Muttalib ibn Hashim ibn AbdManaf ibn Qusayy ibn Kilab ibn Murrah ibn Kab ibn Luwayy ibn Ghalib ibn Fihr (also known as Quraysh). That is showing 12 generations. Now note that Prophet Muhammad's great grandfather was Hashim in this list. And he was a prominent person among the Quraysh tribe of Makkah at his time and his clan are known as Hashimi. Thus, Prophet Muhammad is both Qurayshi and Hashimi.
The second issue is in Arab names is that it was common practice to call a person by the name of his eldest son. In Arabic, "Abu" mean father. Thus, Prophet Muhammad is also known by the name of Abu'l-Qasim, meaning the father of Qasim. Caliph Ali is known as Abu'l-Hasan, i.e. father of Hasan. That is how people would address them. And in books you will find that this name is also considered to be a part of the person's name. So caliph Ali would be Abu'l-Hasan Ali ibn Abi Talib ibn Abdul Muttalib ibn ....
The third issue is that many people were given honorific names which reflected some key element of their character. For example, caliph Umar ibn Al-Khattab (Umar son of al-Khattab) is also known as Umar al-Farooq. Now, Farooq is not a name given at birth. This is a name he acquired because of his keen distinguishing mind. This honor was given to him by the Prophet. His descendants are known as Farooqi.
Likewise, caliph Abu Bakr was given the honorific name of Siddiq (the truthful one) by the Prophet, and thus he is known as Abu Bakr al-Siddiq. His descendants are known as Siddiqi.
I notice that someone added (Amir-ul-Mu'minin) to the name of Umar ibn al-Khattab. This was NOT his name. After he became caliph, Amir-ul-Mu'minin was the title by which he was addressed by the people. It means the Prince of the Believers. He was the first one to take on this title. After him, all caliphs were also addressed by this title. So it is inappropriate to write this as part of his name. The reason for this title is interesting. His predecessor Abu Bakr (the first caliph) was known as Khalifatu rasul-ullah, meaning the caliph of the Messenger of Allah. Khalifa (caliph) means the one who is a successor. When Umar became caliph, he was called khalifatu khalifatu rasulullah, i.e. the successor of the successor of the messenger of Allah. This became a mouthful. And he realized that his successors would have an even more difficult time with the word khalfa added as an additional prefix each time. Thus the title Amir-ul-Muminin was born.
There are many more issues with names in the geni.com charts particularly for Arab and Muslim names. I have had a difficult time cleaning up a lot of the mess, but I am tired of doing it. For example, many of the present descendants feel that is inappropriate to write only the name of a person without adding a word of respect before the name and also adding some prayers after the name, and showing it as if all of this is part of the name. This is more true with Muslims of the sub-continent and southeast Asia. Let me be more specific with an example.
The word "Hazrat" or "Hadrat" is often added as a first name to the name of an ancestor. This is not a name. It is just a word of high respect and one would not call the ancestor directly by the name except by adding Hazrat. Thus caliph Abu Bakr's name might be written as Hazrat Abu Bakr. Hazrat is often written as Hz. Likewise, I saw somewhere that the caliph Ali ibn Abi Talib's name is written as Maulana Ali. Maulana is not his name. It is another word of respect meaning our lord. or our master. If that is not written, it is considered to be disrespectful. I have seen many other such words added. Another one I encountered was "Qibla" which sufis often use to denote that our direction is towards that person just like Muslims face the Kabah which is considered to be qibla.
As mentioned above, words of prayer are also added at times. So you might see a phrase like "rahimahullah" or "rahmatullah alayh" or "alayhis salam", etc added to a name. The first two mean "may God's mercy be upon him", and the third one means "may peace be upon him". It is considered anathema by many to refuse to utter or write these prayers after the person's name. There are numerous such phrases and prayers I have come across.
Frankly, the way the names of very large number of the people written is misleading because of these issues. Or maybe i should say that we are trying to plug these names into the Western method of naming people by forenames and middle names and surnames. It doesnt work. You cannot resolve these data conflicts so easily unless geni.com were to devise a better way of recording this data and data points.
I have highlighted some of the main issues. There are several more issues which would need more detailed analysis. For example, I have not even touched upon political and religious titles given which are also shown as part of the names in several cases.
My apologies for any typo mistakes above as I wrote this in a hurry.