Cultivar Stability

[Chemotype]

I know the answer to this question depends on the cultivar and source of the seed, but how stable are most cultivars sold by commercial seed companies? How many phenotypes are usually expected?

For example, strains like:

Somango- Soma Seeds
Kali Mist- Serious Seeds
Hindu Kush – Sensi Seeds
Afghanica - Flying Dutchmen
Super Skunk – Sensi Seeds