Can I setup several mariadb clusters, each for a schema I'm planning to use MariaDB Cluster, as a way to sync several databases from different peripherals (raspberry pis). 
The peripherals don't share data, but all data should be shared with the main server.

Is there a way to keep the same database, but create a cluster with 2 nodes for each schema ?

Thanks
If the Pis are the source of the data, use "multi-source" replication from them to MariaDB.

Then have 3 nodes for the cluster (2 is mostly useless), and have all the data for both databases on all the nodes.

Or, more simply, the 2 Pis replicate to a single Master (no cluster).