The phrasal verb "treat alike" would do well here.
I treat all my children alike.
I treat you and the other customers alike.
They treat educated and ordinary people alike.
In all these cases, note that the two words of the verb are split. That's fairly common in English.
Sometimes, you might be able to get away with "commingle", but that has more to do with dumping all together in the same bucket than treating identically: it's closely related, but not quite the same thing. Here, only the second sentence can really get away with it, and not very well; it's silly to talk about putting one's children all in the same house (who doesn't?), and almost as silly to talk about putting people in the same places regardless of education. But putting all one's customers in the same queue for the cash register or ticket counter is reasonable enough, and, crucially, so is putting them in different queues.
None of commingle's synonyms are at all useful here.