Feature-Request: Support multiple Stream-Ids per event?

[anti-held-333]

Hey ho,
Is it possible to support multiple stream-ids and an additional stream-category per event. That would simplify e.g. the building of some projections.
Example:

• A Service is responsible for managing articles (e.g. edit some attributes etc.)
• Another service manages batches of the service. (generates new ones etc.)
  • Some parts of the business logic to generate those batches is based on the article attributes. <- We need those information in our service.

  To build the state it would be handy to get the Events in correct order from multiple streams (e.g. art_1337 and batch_1337_no1)

To simplify building a projection which list the articles with its attributes and the corresponding batches, it would be nice e.g. to use some batch-service events (e.g. BatchReleasedForSale) during building that projection. (So it would be nice the let the BatchReleasedForSale Event to be listed on multiple streams like art_1337 and batch_1337_no1)

The current approach (with only 1 Stream-ID) needs to write an additional logic to forward events from one service to another.

Put up for discussion: This can lead to a closer coupling of services. So would it be bad practice?