Any node with full permissions can issue news assets onto the blockchain to synch with other nodes. There is no use-case I can think of that would require you to lock down a node to issuing a specific asset, only.
I think that you may be thinking of the blockchain as a traditional database, where one database table can only store a certain set of data for example.
With blockchain, all nodes are in synch with each other (and catch up to current block height if not). You can issue any asset from any multichaind connected to the blockchain. If you issue "Asset001" on "Node 3" then "Node 1, Node 2" will synch "Asset001" to their local store.
Does this help?
