Given that the colonies were not created in empty space, it may not have been necessary to equip each and every group of colonists with the skills needed to be self sufficient.
Assuming, further, that it was desired to reduce the number of people sustained on Greek soil, and some colonies were compulsory, they may not have asked for model craftsmen, farmers,…
In spite of the above, I suspect that it was a patently bad idea to send a trireme full of poets and dancing masters, trusting that some neighbouring city would have helped them to establish their own city.
Rather, some sensible rules must have been observed prior to leaving the metropolis (mother city). I suspect they stipulated:
- sending someone who knew about canalisation
- sending numerous experienced farmers
- ~~sending priests ~~ Here I was likely mistaken. The literature appears to indicate that priests were often „just“ respected members of the community
- sending doctors
- sending shipbuilders
Do we know about the existence of such requirements or perhaps even have a record stating some?
Edit: As helpfully observed in the comments, the most important Greek colonisations predated the bulk of literary evidence. There were, however, a few colonies established in the 4th and even 3rd century BC (for examples in the region of the Euxine Sea, see here). Therefore we need not relinquish all hope.