The fact that only two of the disciples specifically called by Jesus are said to have left their father is irrelevant to the larger point that is being made. The simple mention of leaving their father, when called by the one that is worshiped as the embodiment of the Creator God by the community that is hearing the story, creates an Abrahamic frame of reference that can be comfortably applied to the rest of the callings. In this Abrahamic light then, one can take a moment to stretch the analogy just a bit further, calling attention to the fact that James and John are said to have taken the action to leave their father together.
The call of Abraham, according to the Genesis narrative, was to “Go out from your country, your relatives, and your father’s household.” However, those that know the Abraham story know that Abraham took his nephew Lot with him. So even though these two disciples (James and John), unlike Abraham, did indeed make the difficult decision to leave their father (Zebedee), that decision was made a little bit easier, as each man did so in conjunction with his brother. The fact that the first four called disciples are said to have been business partners, at least according to Luke, probably made the decision to leave their occupations and to follow Jesus just slightly less tenuous.
Is the call from Jesus to follow Him, combined with an account of leaving a father behind the extent of the similarities to the call of Abraham? Of course not. That would hardly be enough of a basis from which to build a credible argument. Considering that the covenant God’s redemptive plan for His creation begins with Abraham, climaxes with Jesus and is to be continually carried out through His disciples through the time of the consummation of His kingdom and beyond, there must be far more points of contact between the Abrahamic covenant and the call to discipleship. Fortunately, there are.
Returning to Mark’s Gospel then and venturing to the third chapter, it is there found that Jesus “appointed twelve (whom He named apostles), so that they could be with Him and He could send them to preach and to have authority to cast out demons. He appointed twelve” (3:14-16a). The duplication of “appointed twelve” could easily be heard as an emphasizing of the re-gathering of the twelve tribes of Israel. As the Creator God ordained Israel to be a light to the nations, so too Jesus has ordained twelve to the same end. Naturally, any implicit references to the Creator God’s covenant with Israel also carries with it an implicit reference to the Abrahamic covenant, as there is no Israel without Abraham, and there would be no Mosaic covenant without the Abrahamic covenant.
So in coming to understand the Abrahamic mental triggers that would be pulled by the appointment of twelve, one can then make a rather broad analysis based on what it is that Mark says next. If the Abrahamic and Mosaic covenants are in mind when Mark writes “so they would be with Him and He could send them,” then this is yet another recapitulation of the long-standing charge to Israel, for the Creator God had promised Israel that He would dwell among them if they were faithful to the obligation to carry out His commandments. Ultimately, this dwelling among them would be for the purpose of their revealing His glory to all peoples. Certainly this can be seen as Israel both being with their God and being sent by their God. If that is the case, then one is forced to revert further to that which is foundational to Israel’s relationship with their God, which is the promise to Abraham.