They were still apostles non the less, and the Lord told Peter he was given the keys to the kingdom and chosen to lead the church. In that Peter was given the right to carry on the appointing of others, and so was Paul. In 1 Timothy Paul shows then when he tells Timothy do not ordain/appoint just anybody.
Even Paul understood that each had his own work to do...
1Co 12:3 Wherefore I give you to understand, that no man speaking by the Spirit of God calleth Jesus accursed: and that no man can say that Jesus is the Lord, but by the Holy Ghost.
1Co 12:4 Now there are diversities of gifts, but the same Spirit.
1Co 12:5 And there are differences of administrations, but the same Lord.
1Co 12:6 And there are diversities of operations, but it is the same God which worketh all in all.
1Co 12:7 But the manifestation of the Spirit is given to every man to profit withal.
1Co 12:8 For to one is given by the Spirit the word of wisdom; to another the word of knowledge by the same Spirit;
1Co 12:9 To another faith by the same Spirit; to another the gifts of healing by the same Spirit;
1Co 12:10 To another the working of miracles; to another prophecy; to another discerning of spirits; to another divers kinds of tongues; to another the interpretation of tongues:
1Co 12:11 But all these worketh that one and the selfsame Spirit, dividing to every man severally as he will.
Some here don't.