No. przemek’s comment about “no way to get conflicts” is only for inserts. That’s because Percona/Galera will set auto_increment_increment and auto_increment_offset, so node1 will create IDs 1, 4, 7, etc, node2 will create IDs 2, 5, 8, etc, and node3 will create IDs 3, 6, 9, etc. HOWEVER, “writes” can be inserts, updates, or deletes. And if you try to update the same record on two different nodes simultaneously, you have the potential for a conflict. Best approach is to expect that if it can happen, it will, especially if you’re expecting any level of scale.
You could hypothetically distribute writes to different nodes by designating an “owner node” for each DB or even table (though the latter case would be more complicated). For example, if your cluster is hosting three DBs, you could direct all DB1 writes to node1, all DB2 writes to node2, and all DB3 writes to node3. Row-based replication (RBR) makes updates faster on the replicated nodes so this would improve your scalability some, though maybe not worth the extra management effort.