Well, let's focus on one pair of holes at the very left of your print for a moment. The way I saw an application of common zone modifier was something like:
1. Remove datum feature symbol A.
2. Apply prefix '2X' to [ø]60 dimension.
3. Apply [ø]0.2 concentricity tolerance with CZ modifier to [ø]60 dimension, however without any datum reference in feature control frame (FCF). For this dimensioning scheme you would not like to have datum reference A, because CZ modifier would create one common cylindrical zone for both holes.
The next step would be to define mutual relationship between left pair of holes and remaining two pairs. I would try do it in a following way:
4. Add datum feature symbol A to concentricity tolerance FCF described in point #3.
5. Define 2X [ø]60 dimension for center and right pair of holes.
6. Define basic (theoretically exact) dimensions between axis of left pair of holes and axes of two other pairs.
7. Assign [ø]0.2 positional tolerance with relation to datum A to both [ø]60 dimensions described in point #6.
There is also another way, much easier, and absolutely legal per ISO standards. You could apply single [ø]60 dimension with prefix '6X', tie the axes of holes together by basic dimensions and assign [ø]0.2 positional tolerance with or without any datum reference, depending whether a control of orientation and/or location of the pattern relative to any external features is needed. With this approach 6 holes would be treated as a single pattern so the relationship of coaxiality within each pair of holes would be automatically controlled. The advantage of such scheme would be that none of the pair of holes would be favoured over the other two pairs, which I think would better reflect the functionality of the system.
