What should be the priority?
As a general rule, especially when learning to pitch, power pitchers are going to be a more inconsistent, while control pitchers will throw more strikes. If you have power pitchers it is definitely more frustrating and takes more patience but it will work itself out over time. Most pitchers I have seen that throw a lot of strikes early in their learning are control pitchers (less velocity), and they tend to remain control pitchers throughout there careers. Again not always but usually, and there is a place for both.