I don't understand the relationship between the original question and this question:
is there any other way to archive a single search on a great number of indices
wildcards won't do I'm affraid
Searching for
GET foo*/_search
is fine.
It's unclear to me what you are trying to achieve here.
Could you provide a full recreation script as described in About the Elasticsearch category. It will help to better understand what you are doing. Please, try to keep the example as simple as possible.
A full reproduction script will help readers to understand, reproduce and if needed fix your problem. It will also most likely help to get a faster answer.