So I took another look at Aktau... and Running:
0 Priests (max food) = We get 5

(8 Turns for Knight), 0 GP points (no progress towards holy building), Growth in 2 turns (not 1).
3 Priests (max food) = We get 7

(6Turns for Knight), 18 GP points (I forgot that Philo trait give +100% GP points), Growth in 5 turns (not 7 or 3).
3 Priests, 1 Engineer (max food) = We get 8

(5 Turns for Knight), 24 GP points, Neutral Growth.
At Pop 6 Aktau was already working all the improved tiles, so to quote a famous Kaz'er...if it grows, "it would be working unimproved tiles, what would be the point of that?" Even with the grassland farmed, it only produces food. So we would get another pop point that would work a tile that only makes food which = no benefit. Better to run a priest or engineer at neutral growth.
If we grow one pop point, we will be at happy cap, but that pop point will have to be applied to food to prevent starvation. There is no point in doing that. We can run 4 specialist RIGHT NOW and be growth neutral. Once the graslands are farmed, and a

face goes away, we can grow the city again, while still running specialists.
Running an engineer gives us more

(3) then we could get from working any other combination of tiles that would give growth. It also speeds along our Prophet (with more GP points), and creates a possiblility of a Great Engineer, which would be good for rushing Apostolic Palace.
After considering all of this, I went with option 3. Once grassland is farmed by worker near Aktau, and happy cap is more, we can grow the city again.
AND yes I sent the Caravel South-East to put it outside of SANCTA's view.