Sure, why not. Grant required privileges and INSERT INTO target_table SELECT * FROM source_table. Repeat the above as many times as there are tables in those schemas. Don't forget to create scripts for copying other objects (stored procedures, packages, functions, triggers, ...). To do that, research use of DBMS_METADATA.
However, why do you not want to use export/import? It looks like you'd want to dig a deep hole, but don't want to use a shovel and would like to use spoon instead. Possible, but with much more pain. So: why not export/import as it is designed to move data around?
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For most folks, they don't know, what they don't know.
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