"We have made the Qur'an easy in your language so that they may take heed it." (Qur'an 44:58). Yet if this was true, then we would expect that different Muslims would reach the same conclusions pertaining to cases of inheritance. But do they?

Please now consider the case in which a husband dies, and leaves as his sole heirs his wife and his 2 parents.  His mother would receive 1/3 of his estate according to Quran 4:11: "...and if he have no child and his parents are his heirs, then to his mother a third ..."  Quran 4:12 indicates that the wife would get 1/4 of the estate:  "...And unto them [the wives or wife] belongs the fourth of that which you leave..." And the father would get the rest (5/12 of the estate), since Muhammad had decreed:  "The Prophet said, "Give the Fara'id, (the shares prescribed in the Qur'an) to those who are entitled to receive it, and then whatever remains, should be given to the closest male relative of the deceased." [Sahih Bukhari, Volume 8, Book 80, Number 729}.  The Islamic Inheritance Calculator found at Lubnaa.com Inheritance Calculator  yields exactly these fractions for the 3 heirs (that is, 1/4 for the wife, 1/3 for the mother, and 5/12 for the father).
HOWEVER, other Muslims (and other Islamic Inheritance Calculators) note that because of Quran 4:11,if instead only the parents were heirs the mother would still get 1/3 of the estate; should not this portion be reduced by the presence of an additional close heir, the wife?  That is to say, the portion for the father decreases, from two-thirds (with the parents the only heirs) to 5/12 if the deceased had a wife, so why should the mother's share remain unchanged?  If this is undesirable, we observe that the father gets twice what the mother receives if only the parents are heirs -- one can retain this 2 to 1 ratio between the parents even if the wife too is also an heir. That is to say, if the wife gets 1/4 of the estate, you could apportion the rest so that the mother gets 1/4 and the father gets twice that of the mother, or 1/2.  This rule of inheritance for this case is attributable to Islam's second caliph, Omar, who led the Muslims not long after Muhammad's death.  Islamic Inheritance Calculators such as IRTH: The Islamic Inheritance Program and Islamic Inheritance Calculator use Omar's rule to get 1/4 for both wife and for mother, and 1/2 for the father.  Yet Omar's rule is found neither in the Quran nor among the other sayings of Muhammad, and Omar was not "A Prophet of Allah."
So Muslims disagree on how to handle this particular inheritance case.  Moreover, pertinent disagreements between Shia Muslims and Sunni Muslims with regards to other inheritance cases can be found at this link.  Our Debate Question is "Has the Quran been "made easy," or could Muhammad and Allah made inheritance instructions more clear?"