All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
In principle, it is an obligation that water reaches all the parts of ablution (face, hands, head, and feet). Allah says {What means}: " O ye who believe! when ye prepare for prayer, wash your faces, and your hands (and arms) to the elbows; Rub your heads (with water); and (wash) your feet to the ankles." {Al-Ma`idah, 6}.
These body parts must be washed in order, and the order is the sixth pillar among the pillars of ablution according to the Shafi'i school. It is mentioned in {Hashiyat Al-Bajuri, (Vol.1, P.258)} : "The sixth (pillar) is order, meaning: it is one of the obligations of ablution, which is arranging everything in its proper order."
If a person who is in a state of ritual impurity, major or minor, immerses himself or herself in a large amount of water, there are two scenarios:
First: Immersing oneself to remove the minor ritual impurity, in which case it is obligatory to make an estimated order of the acts of ablution. Moreover, the intention to remove the minor impurity must be concurrent with the first contact of water with one`s face. A person`s ablution is considered valid by immersion because it encompasses all the essential parts of ablution with water, and the order is achieved in a short moment. This is in line with the opinion of Imam al-Bajuri, may Allah have mercy on him, as mentioned in his commentary [Hashiyat al-Bajuri, Vol. 1/P.258]: "If the person in a state of minor impurity immerses himself, intending ablution, it suffices, even if he does not stay submerged, because the order is achieved in a brief moment. However, the intention must be concurrent with the first contact of water with the face, as the intention is necessary during the first washing of the face."
Second: Immersion to remove major ritual impurity. In this case, there is no obligation for a specific order since the removal of minor ritual impurity is encompassed automatically within the removal of major ritual impurity since the body is treated as a single unit in Ghusl of Janabah (Ghusl performed after sexual intercourse/ejaculation).
Imam al-Bajuri, may Allah have mercy on him, said: "The situation in which the order becomes obligatory is when there is no major impurity. Otherwise, the order is dropped because the smaller impurity is included in the major one." {Hashiyat al-Bajuri, Vol. 1/P.258}.
In conclusion, if someone experiencing minor ritual impurity fully immerses themselves in an ample amount of water (more than two qullas) with the intention of removing the impurity, their ablution is valid, even if they do not remain in that state for a duration that allows for the specific order. And Allah the Almighty knows best.