We have numerous time where the Holy Spirit "come" or "fills" people, here is a sample:
- John 20:22 - When He had said this, He breathed on them and said, “Receive the Holy Spirit
- Acts 2:3, 4 - They saw tongues like flames of fire that separated and came to rest on each of them. And they were all filled with the Holy Spirit ...
- Acts 4:8 - Then Peter, having been filled with the Holy Spirit, said to them ...
- Acts 4:31 - After they prayed, the place where they were meeting was shaken. And they were all filled with the Holy Spirit and spoke the word of God boldly.
- Acts 7:55 - But Stephen, full of the Holy Spirit, looked straight into heaven and saw the glory of God and Jesus standing at the right hand of God.
- Acts 9:17 - Brother Saul, the Lord--Jesus, who appeared to you on the road as you were coming here--has sent me so that you may see again and be filled with the Holy Spirit
- Acts 13:9 - Then Saul, who was also called Paul, filled with the Holy
Spirit, looked straight at Elymas and said ...
Note that in many cases, it is the same people repeatedly said to be "full of the Holy Spirit" - it appears to be constant state of being for these people, especially the apostles.
Now, we must distinguish between two types of references - those that say a person was full or filled with the Spirit (eg, Acts 13:9) and those that say the Holy Spirit came upon those that did not have this gift previously (eg, Acts 19:6).
Thus, John 20:22 records Jesus bequeathing the gift of the Holy Spirit to the disciples and Acts 2:3, 4, 4:8, 31, etc, where the disciples are described as already filled (perfect tense or aorist tense) with the Holy Spirit.
Therefore, I see no priority nor chronological problem here. Jesus statement in John 16:7 means what a simple reading reveals, the comforter (parakletos) would be sent shortly afterward.
Now, there is one more subtlety. Jesus declared in John 16:7 that unless Jesus went away the Holy Spirit would not come to the disciples. Since we receive the gift of the Holy Spirit by faith, while Jesus was personally and physically present with the disciple, it would have been humanly almost impossible for them to exercise that faith to receive "another" comforter. Hence Jesus remark.
It was when Jesus physically departed that the disciples finally recognized the Spirit's presence and power, when their faith was not "blinded by sight".